U.S. patent application number 12/349773 was filed with the patent office on 2010-01-14 for pyrazine derivatives, methods of use, and methods for preparing same.
This patent application is currently assigned to Mallinckrodt Inc.. Invention is credited to Richard B. Dorshow, John Freskos, William L. Neumann, Amruta Reddy Poreddy, Raghavan Rajagopalan.
Application Number | 20100010223 12/349773 |
Document ID | / |
Family ID | 40845814 |
Filed Date | 2010-01-14 |
United States Patent
Application |
20100010223 |
Kind Code |
A1 |
Dorshow; Richard B. ; et
al. |
January 14, 2010 |
Pyrazine derivatives, Methods of use, and methods for preparing
same
Abstract
The present invention relates to methods for producing
N,N'-alkylated diaminopyrazines.
Inventors: |
Dorshow; Richard B.; (St.
Louis, MO) ; Freskos; John; (Clayton, MO) ;
Neumann; William L.; (St. Louis, MO) ; Poreddy;
Amruta Reddy; (St. Louis, MO) ; Rajagopalan;
Raghavan; (St. Peters, MO) |
Correspondence
Address: |
Mallinckrodt Inc.
675 McDonnell Boulevard
HAZELWOOD
MO
63042
US
|
Assignee: |
Mallinckrodt Inc.
Hazelwood
MO
|
Family ID: |
40845814 |
Appl. No.: |
12/349773 |
Filed: |
January 7, 2009 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61080207 |
Jul 11, 2008 |
|
|
|
61082296 |
Jul 21, 2008 |
|
|
|
Current U.S.
Class: |
544/407 |
Current CPC
Class: |
A61P 13/12 20180101;
C07D 241/28 20130101 |
Class at
Publication: |
544/407 |
International
Class: |
C07D 241/10 20060101
C07D241/10 |
Claims
1. A method for producing a N,N'-alkylated diaminopyrazine, the
method comprising: combining a diaminopyrazine compound and a
carbonyl compound in the presence of a reducing agent.
2. The method of claim 1, wherein the combining comprises combining
the diaminopyrazine compound, the carbonyl compound, and a solvent
in the presence of the reducing agent.
3. The method of claim 2, wherein the combining occurs at a
temperature between about -20.degree. and about 50.degree. C.
4. The method of claim 1, wherein the combining occurs at a
temperature between about -20.degree. and about 50.degree. C.
5. The method of claim 1, wherein the combining occurs at a
temperature between about -5.degree. and about 30.degree. C.
6. The method of claim 1, wherein the carbonyl compound is of the
following Formula III below, and wherein: ##STR00026## each of
R.sup.1 and R.sup.2 is independently hydrogen, C.sub.1-C.sub.10
alkyl, C.sub.5-C.sub.20 aralkyl, C.sub.1-C.sub.20 hydroxyalkyl,
C.sub.2-C.sub.20 polyhydroxyalkyl,
--(CH.sub.2).sub.nCO.sub.2R.sup.3,
--(CH.sub.2CH.sub.2O).sub.mR.sup.4, or mono- or poly-saccharide
containing 1 to 50 units; each of m and n is independently 1, 2, 3,
4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50; and each of
R.sup.3 and R.sup.4 is independently hydrogen, C.sub.1-C.sub.10
alkyl, C.sub.5-C.sub.20 aralkyl, C.sub.1-C.sub.10 acyl,
C.sub.1-C.sub.20 hydroxyalkyl, C.sub.2-C.sub.20 polyhydroxyalkyl,
or mono- or poly-saccharide containing 1 to 50 units.
7. The method of claim 6, wherein each of m and n is independently
is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30.
8. The method of claim 6, wherein each of R.sup.3 and R.sup.4 is
independently hydrogen, C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.20
hydroxyalkyl, or C.sub.2-C.sub.20 polyhydroxyalkyl.
9. The method of claim 1, wherein the diaminopyrazine compound is
of the following Formula II or III below, wherein: ##STR00027##
each of X and Y is independently hydrogen, C.sub.1-C.sub.10 alkyl,
--OR.sup.5, --SR.sup.6, --NR.sup.7R.sup.8, --N(.sup.9)COR.sup.10,
halo, trihaloakyl, --CN, --NO.sub.2, --CO-Z-R.sup.11, --SOR.sup.12,
--SO.sub.2R.sup.13, --SO.sub.2OR.sup.14, or
--PO.sub.3R.sup.15R.sup.16; Z is a single bond, --O--,
--NR.sup.17--, --NH(CH.sub.2).sub.pNH--, --NH(CH.sub.2).sub.pO--,
--NH(CH.sub.2).sub.pCO--, --NH(CH.sub.2).sub.pNHCO--,
--NH(CH.sub.2).sub.pCONH--, --NH(CH.sub.2).sub.pNHCONH--,
--NH(CH.sub.2).sub.pNHCSNH--, or --NH(CH.sub.2).sub.pNHCO.sub.2--;
p is 0, 1, 2, 3, 4, 5 or 6; each of R.sup.5 to R.sup.17 is
independently hydrogen, C.sub.1-C.sub.10 alkyl, C.sub.5-C.sub.20
aralkyl, C.sub.1-C.sub.10 acyl, C.sub.1-C.sub.20 hydroxyalkyl,
C.sub.2-C.sub.20 polyhydroxyalkyl,
--(CH.sub.2CH.sub.2O).sub.qR.sup.18, or mono- or poly-saccharide
containing 1 to 50 units; q is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28,
29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45,
46, 47, 48, 49 or 50; and R.sup.18 is hydrogen, C.sub.1-C.sub.10
alkyl, C.sub.5-C.sub.20 aralkyl, C.sub.1-C.sub.10 acyl,
C.sub.1-C.sub.20 hydroxyalkyl, C.sub.2-C.sub.20 polyhydroxyalkyl,
or mono- or poly-saccharide containing 1 to 50 units.
10. The method of claim 9, wherein each of X and Y is
--CO-Z-R.sup.11.
11. The method of claim 10, wherein R.sup.11 is hydrogen,
C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.20 hydroxyalkyl, or
C.sub.2-C.sub.20 polyhydroxyalkyl.
12. The method of claim 10, wherein Z is --NR.sup.17--.
13. The method of claim 12, wherein R.sup.17 is hydrogen or
C.sub.1-C.sub.10 alkyl.
14. The method of claim 10, wherein Z is
--NH(CH.sub.2).sub.pNH--.
15. The method of claim 14, wherein p is 0, 1, 2, 3 or 4.
16. The method of claim 10, wherein Z is
--NH(CH.sub.2).sub.pCO--.
17. The method of claim 16, wherein p is 0, 1, 2, 3 or 4.
18. The method of claim 9, wherein each of X and Y is --CN.
19. The method of claim 1, wherein the reducing agent comprises
ammonium formate, diimide, Zn/HCl, sodium triacetoxyborohydride,
sodium borohydride, pyridine/borane, lithium aluminium hydride,
lithium borohydride, sodium cyanoborohydride, sodium amalgam,
H.sub.2/Pd/C, H.sub.2/Pt/C, H.sub.2/Rh/C, and H.sub.2/Raney.RTM.
Nickel, or any combination thereof.
20. The method of claim 1, wherein the reducing agent comprises
sodium triacetoxyborohydride.
21. The method of claim 1, wherein the reducing agent comprises
sodium cyanoborohydride.
22. The method of claim 2, wherein the solvent comprises water,
C.sub.1-C.sub.8 alcohol, C.sub.1-C.sub.8 ether, C.sub.1-C.sub.8
ester, dimethyl formamide, dimethyl acetamide, acetic acid,
trifluoroacetic acid, dimethyl sulfoxide, or any combination
thereof.
23. The method of claim 2, wherein the solvent is essentially
methanol, ethanol, isopropyl alcohol, tetrahydrofuran, dioxane,
glyme, dimethyl formamide, dimethyl sulfoxide, or any combination
thereof.
Description
RELATED APPLICATIONS
[0001] This application claims priority to U.S. provisional
application Ser. Nos. 61/080,207 and 61/082,296 filed on 11 Jul.
2008 and 21 Jul. 2008 (respectively), both of which are entitled
"Pyrazine Derivatives, Methods of Use, and Methods for Preparing
Same," and both of which are incorporated by reference herein to
the extent their teachings are not inconsistent with that of the
present application.
FIELD
[0002] The present invention relates to methods for producing
pyrazine derivatives, and particularly, methods for producing
N,N'-alkylated diaminopyrazines.
INTRODUCTION
[0003] The ability to continuously monitor renal function via the
glomerular filtration rate (GFR) in the clinic is currently an
unmet medical need.[1-5] Monitoring of renal function is important
to reduce the risk of acute renal failure caused by clinical,
physiological, and pathological conditions. It is particularly
important in the cases of critically ill or injured patients, since
these patients tend to frequently face the risk of multiple organ
failure and death.[6, 7]
[0004] Currently, the most common method of gauging renal function
is serum creatinine measurement at frequent intervals over a
24-hour period.[8, 9] The results are often misleading, given that
the concentration is affected by age, hydration state, renal
perfusion, muscle mass, diet and many other anthropometric and
clinical variables.[10]
[0005] An accurate, real-time measure of renal excretion rate using
exogenous markers would represent a substantial improvement over
current practices. It would also be desirable to provide a process
that allows for less subjective interpretation based upon age,
muscle mass, blood pressure, etc. Exogenous markers such as
insulin, iothalamate, .sup.51Cr-EDTA, Gd-DTPA, and .sup.99mTc-DTPA
may be used to measure GFR.[11-13] Other markers such as .sup.123I
and .sup.125I labeled o-iodohippurate or .sup.99mTcMAG.sub.3 may be
used to assess the tubular secretion process.[14] Unfortunately,
these markers and methods suffer from drawbacks such as the use of
radioactivity and/or ionizing radiation. These limitations make
them undesirable for a number of medical uses (e.g., real-time,
bedside renal function monitoring).
SUMMARY
[0006] Among the various aspects of the present invention are
pyrazine derivatives that may be detected in vivo and used in a
number of medical procedures (e.g., renal function monitoring).
Without being bound by a particular theory, the pyrazine
derivatives described herein may be designed to be hydrophilic
and/or have rigid functionality, thus allowing for rapid renal
clearance while providing desired pharmacokinetic properties for
monitoring renal function.
[0007] A first aspect of the invention is directed to pyrazine
derivatives, each of which has a pyrazine ring. A carbon of the
pyrazine ring has a substituent bonded thereto that includes a
group selected from urea, amide, sulfonamide, thiourea, carbamate,
or any combination thereof. In this pyrazine derivative, at least
one occurrence of an above-mentioned group is separated from the
carbon of the pyrazine ring to which the substituent is bonded by
at least two atoms. For example, the substituent may include one of
the aforementioned groups that is bonded directly to the carbon as
long as the substituent also has at least one occurrence of one of
the aforementioned groups that is separated from the carbon of the
pyrazine ring to which the substituent is bonded by at least two
atoms.
[0008] With regard to the pyrazine derivatives of the first aspect
of the invention, at least one occurrence of the group may be
separated from the carbon of the pyrazine ring to which the
substituent is bonded by other appropriate atom spacings. For
instance, in some embodiments, at least one occurrence of an
aforementioned group is separated from the carbon of the pyrazine
ring to which the substituent is bonded by at least three atoms. In
other embodiments, at least one occurrence of an aforementioned
group is separated from the carbon of the pyrazine ring to which
the substituent is bonded by at least four atoms. In still other
embodiments, at least one occurrence of an aforementioned group is
separated from the carbon of the pyrazine ring to which the
substituent is bonded by at least five atoms. And in even other
embodiments, at least one occurrence of an aforementioned group is
separated from the carbon of the pyrazine ring to which the
substituent is bonded by at least six atoms.
[0009] Still referring to the pyrazine derivatives of the first
aspect of the invention, in some embodiments, each occurrence of an
aforemention group may be separated from the carbon of the pyrazine
ring to which the substituent is bonded by at least two atoms. In
other words, in these embodiments, no portion of a urea, amide,
sulfonamide, thiourea, carbamate, or any combination thereof is
located within two atoms of the carbon (of the pyrazine ring) to
which the substituent is bonded. In some embodiments, each
occurrence of the group may be separated from the carbon of the
pyrazine ring to which the substituent is bonded by at least three,
at least four, at least five, or even at least six atoms.
[0010] In some embodiments of the first aspect, each of the four
carbons of the pyrazine ring has a substituent bonded thereto. In
such embodiments, each occurrence of an aforemention group of any
of the four substituents may be separated from the carbon of the
pyrazine ring to which the substituent is bonded by at least two
atoms. In other embodiments, each occurrence of an aforementioned
group of any of the four substituents may be separated from the
carbon of the pyrazine ring to which the substituent is bonded by
at least three, at least four, at least five, or even at least six
atoms.
[0011] Still referring to pyrazine derivatives of the first aspect,
in some embodiments, a first carbon of the pyrazine ring has a
first substituent bonded thereto that includes a first group
selected from urea, amide, sulfonamide, thiourea, carbamate, and
any combination thereof. Further, a second carbon of the pyrazine
ring has a second substituent bonded thereto that includes a second
group selected from urea, amide, sulfonamide, thiourea, carbamate,
and any combination thereof. In such embodiments, the first group
is separated from the first carbon of the pyrazine ring by at least
two atoms, and the second group is separated from the second carbon
of the pyrazine ring by at least two atoms. The first group may be
the same as or different from the second group. For instance, in
the case that the first group is the same as the second group, the
first group and the second may each be an amide. As another
example, the first group and the second group may each be a urea.
In some embodiments, the first substituent that is bonded to the
first carbon of the pyrazine ring may be the same as or different
from the second substituent.
[0012] The first carbon and the second carbon may be located in any
appropriate positions along the pyrazine ring. For instance, in
some embodiments, the first carbon of the pyrazine ring is para to
the second carbon of the pyrazine ring. In other embodiments, the
first carbon of the pyrazine ring is meta to the second carbon of
the pyrazine ring.
[0013] In embodiments having a first substituent that is bonded to
a first carbon and a second substituent that is bonded to a second
carbon, the first and second substituents may include any of a
number of other appropriate groups besides each including at least
one of the groups mentioned above (e.g., urea, amide, sulfonamide,
thiourea, carbamate, and/or any combination thereof) For instance,
in some embodiments, at least one of the first and second
substituents may include at least one polyethylene glycol (PEG)
unit (e.g., a plurality of PEG units). Incidentally, a "PEG unit"
herein refers to a CH.sub.2CH.sub.2O unit. In some embodiments,
each of the first and second substituents comprises at least one
PEG unit. For example, in some embodiments, the first substituent
may include a plurality of PEG units, and the second substituent
may also include a plurality of PEG units.
[0014] A second aspect of the invention is directed to pyrazine
derivatives, each of which includes a pyrazine ring that comprises
a first carbon, a second carbon, a third carbon, and a fourth
carbon. The first carbon has a first substituent bonded thereto,
the second carbon has a second substituent bonded thereto, the
third carbon has a third substituent bonded thereto, and the fourth
carbon has a fourth substituent bonded thereto. Each of the first,
second, third, and fourth substituents includes a group selected
from urea, amide, sulfonamide, thiourea, carbamate, and any
combination thereof.
[0015] With regard to the second aspect of the invention, the
structure of a given substituent may be same as or different from
one or more other substituents of the pyrazine derivative. For
instance, in some embodiments, the first and second substituents
are the same, and the third and fourth substituents are the same
but different from the first and second substituents. In such
embodiments, the first and second carbons may be para to each other
(which means the third and fourth carbons would also be para to
each other), or the first and second carbons may be meta to each
other (which means the third and fourth carbons would also be meta
to each other).
[0016] In some embodiments of pyrazine derivatives of the second
aspect, each of the first and second substituents includes an
amide. For instance, in some embodiments, each of the first,
second, third, and fourth substituents includes an amide.
[0017] Some embodiments of the pyrazine derivatives of the second
aspect may include at least two of the first, second, third, and
fourth substituents having at least one PEG unit. For instance, in
some embodiments, each of the first and second substituents
comprises at least one PEG unit. As another example, each of the
first, second, third, and fourth substituents may include at least
one PEG unit.
[0018] Yet a third aspect of the invention is directed to pyrazine
derivatives, each of which includes a pyrazine ring. A carbon of
the pyrazine ring has a substituent bonded thereto that includes a
urea group. Further, this urea group is separated from the carbon
of the pyrazine ring to which the substituent is bonded by at least
two atoms. So, at least in theory, the substituent may include one
urea that is bonded directly to the carbon of the pyrazine ring as
long as the substituent also includes at least one other urea that
is separated from the carbon of the pyrazine ring to which the
substituent is bonded by at least two atoms. As another example,
one substituent may include a urea that is bonded directly to one
carbon of the pyrazine ring, and another substituent may include
another urea that is separated from the respective carbon of the
pyrazine ring to which that substituent is bonded by at least two
atoms.
[0019] With regard to the pyrazine derivatives of the third aspect,
at least one occurrence of a urea group may be separated from the
carbon of the pyrazine ring to which the substituent is bonded by
other appropriate atom spacings. For instance, in some embodiments,
at least one occurrence of a urea group is separated from the
carbon of the pyrazine ring to which the corresponding substituent
is bonded by at least three atoms. In other embodiments, at least
one occurrence of a urea group is separated from the carbon of the
pyrazine ring to which the corresponding substituent is bonded by
at least four atoms. In still other embodiments, at least one
occurrence of a urea group is separated from the carbon of the
pyrazine ring to which the corresponding substituent is bonded by
at least five atoms. And in even other embodiments, at least one
occurrence of a urea group is separated from the carbon of the
pyrazine ring to which the corresponding substituent is bonded by
at least six atoms.
[0020] Still referring to the pyrazine derivatives of the third
aspect of the invention, in some embodiments, the substituent
includes multiple occurrences of urea groups, and each occurrence
of a urea group is separated from the carbon of the pyrazine ring
to which the substituent is bonded by at least two atoms. In other
words, in these embodiments, no portion of a urea group is located
within two atoms of the carbon (of the pyrazine ring) to which the
substituent is bonded. In some substituents that include multiple
occurrences of urea groups, each occurrence of a urea group may be
separated from the carbon of the pyrazine ring to which the
substituent is bonded by at least three, at least four, at least
five, or even at least six atoms.
[0021] Still referring to the third aspect, in some embodiments,
each of the four carbons of the pyrazine ring has a substituent
bonded thereto. In such embodiments, each occurrence of a urea
group of any of the four substituents may be separated from the
carbon of the pyrazine ring to which the substituent is bonded by
at least two atoms. In other embodiments, each occurrence of a urea
of any of the four substituents may be separated from the carbon of
the pyrazine ring to which the substituent is bonded by at least
three, at least four, at least five, or even at least six
atoms.
[0022] In pyrazine derivatives of the third aspect, the
substituent(s) may include any of a number of other appropriate
groups besides at least one urea. For instance, in some
embodiments, the substituent that includes the urea may also
include at least one PEG unit (e.g., a plurality of PEG units). In
some embodiments, each of a plurality (e.g., two, three, or four)
of substituents, each of which is bound to a different carbon of
the pyrazine ring, may include at least one PEG unit. For example,
in some embodiments, a first substituent bound to a first carbon of
the pyrazine ring may include a urea and plurality of PEG units,
and a second substituent bound to a second carbon of the pyrazine
ring may also include a urea and a plurality of PEG units. In such
embodiments, the first and second carbons may be either meta or
para to each other.
[0023] Still a fourth aspect of the invention is directed to
pyrazine derivatives, each of which includes a pyrazine ring. A
carbon of the pyrazine ring has a substituent bonded thereto that
includes an amide group. Further, this amide group is separated
from the carbon of the pyrazine ring to which the substituent is
bonded by at least two atoms. So, at least in theory, the
substituent may include one amide that is bonded directly to the
carbon of the pyrazine ring as long as the substituent also
includes at least one other amide that is separated from the carbon
of the pyrazine ring to which the substituent is bonded by at least
two atoms. As another example, one substituent may include an amide
that is bonded directly to one carbon of the pyrazine ring, and
another substituent may include another amide that is separated
from the respective carbon of the pyrazine ring to which that
substituent is bonded by at least two atoms.
[0024] With regard to the pyrazine derivatives of the fourth
aspect, at least one occurrence of an amide group may be separated
from the carbon of the pyrazine ring to which the substituent is
bonded by other appropriate atom spacings. For instance, in some
embodiments, at least one occurrence of an amide group is separated
from the carbon of the pyrazine ring to which the corresponding
substituent is bonded by at least three atoms. In other
embodiments, at least one occurrence of an amide group is separated
from the carbon of the pyrazine ring to which the corresponding
substituent is bonded by at least four atoms. In still other
embodiments, at least one occurrence of an amide group is separated
from the carbon of the pyrazine ring to which the corresponding
substituent is bonded by at least five atoms. And in even other
embodiments, at least one occurrence of an amide group is separated
from the carbon of the pyrazine ring to which the corresponding
substituent is bonded by at least six atoms.
[0025] Still referring to the pyrazine derivatives of the fourth
aspect of the invention, in some embodiments, the substituent
includes multiple occurrences of amide groups, and each occurrence
of an amide group is separated from the carbon of the pyrazine ring
to which the substituent is bonded by at least two atoms. In other
words, in these embodiments, no portion of an amide group is
located within two atoms of the carbon (of the pyrazine ring) to
which the substituent is bonded. In some substituents that include
multiple occurrences of amide groups, each occurrence of an amide
group may be separated from the carbon of the pyrazine ring to
which the substituent is bonded by at least three, at least four,
at least five, or even at least six atoms.
[0026] Still referring to the fourth aspect, in some embodiments,
each of the four carbons of the pyrazine ring has a substituent
bonded thereto. In such embodiments, each occurrence of an amide
group of any of the four substituents may be separated from the
carbon of the pyrazine ring to which the substituent is bonded by
at least two atoms. In other embodiments, each occurrence of an
amide of any of the four substituents may be separated from the
carbon of the pyrazine ring to which the substituent is bonded by
at least three, at least four, at least five, or even at least six
atoms.
[0027] In pyrazine derivatives of the fourth aspect, the
substituent(s) may include any of a number of other appropriate
groups besides at least one amide. For instance, in some
embodiments, the substituent that includes the amide may also
include at least one PEG unit (e.g., a plurality of PEG units). In
some embodiments, each of a plurality (e.g., two, three, or four)
of substituents, each of which is bound to a different carbon of
the pyrazine ring, may include at least one PEG unit. For example,
in some embodiments, a first substituent bound to a first carbon of
the pyrazine ring may include an amide and plurality of PEG units,
and a second substituent bound to a second carbon of the pyrazine
ring may also include an amide and a plurality of PEG units. In
such embodiments, the first and second carbons may be either meta
or para to each other.
[0028] Still a fifth aspect of the invention is directed to
pyrazine derivatives of Formulas I and II below.
##STR00001##
[0029] With regard to Formulas I and II) each of X.sup.1 and
X.sup.2 is independently --CO.sub.2R.sup.1, --COR.sup.2,
--SOR.sup.3, --SO.sub.2R.sup.4, --SO.sub.2OR.sup.5,
--PO.sub.3R.sup.6R.sup.8, or --CONR.sup.7R.sup.9. Each of R.sup.1
to R.sup.7 is independently
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cNR.sup.10CONR.-
sup.11(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.20,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cNR.sup.12CSNR.-
sup.13(CH.sub.2).sub.dCH.sub.2CH.sub.2O).sub.eR.sup.21,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cCONR.sup.14(CH-
.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.22,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cNR.sup.15SO.su-
b.2(CH.sub.2).sub.d(CH.sub.2CH.sub.20).sub.eR.sup.23,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cSO.sub.2NR.sup-
.16(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.24,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cNR.sup.17CO(CH-
.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.25,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cNR.sup.18CO.su-
b.2(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.26,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cOC(O)NR.sup.19-
(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.27, or any
combination thereof. Each of R.sup.8 to R.sup.19 is independently
--H or --CH.sub.3. Each of R.sup.20 to R.sup.27 is independently
--H, --CH.sub.3,
--(CH.sub.2).sub.fNR.sup.28C(O)NR.sup.29(CH.sub.2).sub.g(CH.sub.2CH.sub.2-
O).sub.hR.sup.38,
--(CH.sub.2).sub.fNR.sup.--(CH.sub.2).sub.fC(O)NR.sup.32(CH.sub.2).sub.g(-
CH.sub.2CH.sub.2O).sub.hR.sup.40,
--(CH.sub.2).sub.fS(O).sub.2NR.sup.33(CH.sub.2).sub.g(CH.sub.2CH.sub.2O).-
sub.hR.sup.41,
--(CH.sub.2).sub.fNR.sup.34S(O).sub.2(CH.sub.2).sub.g(CH.sub.2CH.sub.2O).-
sub.hR.sup.42,
--(CH.sub.2).sub.fNR.sup.35C(O)(CH.sub.2).sub.g(CH.sub.2CH.sub.2O).sub.hR-
.sup.43,
--(CH.sub.2).sub.fNR.sup.36C(O)O(CH.sub.2).sub.g(CH.sub.2CH.sub.2-
O).sub.hR.sup.44,
--(CH.sub.2).sub.fOC(O)NR.sup.37(CH.sub.2).sub.g(CH.sub.2CH.sub.2O).sub.h-
R.sup.45, --CO(AA), --CONH(PS), or any combination thereof. Each of
R.sup.28 to R.sup.37 is independently --H or --CH.sub.3. Each of
R.sup.38 to R.sup.45 is independently --H, --CH.sub.3, --CO(AA) or
--CONH(PS).
[0030] Still referring to pyrazine derivatives of Formulas I and II
above, each of Y.sup.1 and Y.sup.2 is independently --OR.sup.46,
--SR.sup.47, --NR.sup.48R.sup.49, --N(R.sup.50)COR.sup.51,
--P(R.sup.52).sub.3, --P(OR.sup.53).sub.3, or
##STR00002##
Z.sup.1 is a single bond, --CR.sup.54R.sup.55, --O, --NR.sup.56,
--NCOR.sup.57, --S, --SO, or --SO.sub.2. Each of R.sup.46 to
R.sup.57 is independently --H, --(CH.sub.2).sub.cOR.sup.68,
--CH.sub.2(CHOH).sub.cR.sup.69, --CH.sub.2(CHOH).sub.cCO.sub.2H,
--(CHCO.sub.2H).sub.cCO.sub.2H,
--(CH.sub.2).sub.cNR.sup.70R.sup.71,
--CH[(CH.sub.2).sub.fNH.sub.2].sub.cCO.sub.2H,
--CH[(CH.sub.2).sub.fNH.sub.2].sub.cCH.sub.2OH,
--CH.sub.2(CHNH.sub.2).sub.cCH.sub.2NR.sup.72R.sup.73,
--(CH.sub.2CH.sub.2O).sub.eR.sup.74,
--(CH.sub.2).sub.cCO(CH.sub.2CH.sub.2O).sub.eR.sup.75,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.58C(O)N-
R.sup.59(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.nOR.sup.76,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.60C(S)N-
R.sup.61(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.77,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kC(O)NR.sup.62(-
CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.78,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kS(O).sub.2NR.s-
up.63(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.79,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.64S(O).-
sub.2(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.80,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.65C(O)(-
CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.81,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.66C(O)O-
(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.82,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kOC(O)NR.sup.67-
(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.83,--(CH.sub.2).sub.aSO.sub-
.3H, --(CH.sub.2).sub.aSO.sub.3.sup.-,
--(CH.sub.2).sub.aOSO.sub.3H, --(CH.sub.2).sub.aOSO.sub.3.sup.-,
--(CH.sub.2).sub.aNHSO.sub.3H, --(CH.sub.2).sub.aNHSO.sub.3.sup.-,
--(CH.sub.2).sub.aPO.sub.3H.sub.2,
--(CH.sub.2).sub.aPO.sub.3H.sup.-,
--(CH.sub.2).sub.aPO.sub.3.sup.=,
--(CH.sub.2).sub.aOPO.sub.3H.sub.2,
--(CH.sub.2).sub.aOPO.sub.3H.sup.-, --(CH.sub.2).sub.aOPO.sub.3, or
any combination thereof. Each of R.sup.58 to R.sup.67 is
independently --H or --CH.sub.3. Each of R.sup.68 to R.sup.83 is
independently --H, --CH.sub.3,
--(CH.sub.2).sub.pNR.sup.81C(O)NR.sup.82(CH.sub.2).sub.q(CH.sub.2CH.sub.2-
O).sub.sR.sup.77,
--(CH.sub.2).sub.pC(O)NR.sup.83(CH.sub.2).sub.q(CH.sub.2CH.sub.2O).sub.sR-
.sup.79,
--(CH.sub.2).sub.pS(O).sub.2NR.sup.84(CH.sub.2).sub.q(CH.sub.2CH.-
sub.2O).sub.sR.sup.81,
--(CH.sub.2).sub.pNR.sup.85S(O).sub.2(CH.sub.2).sub.q(CH.sub.2CH.sub.2O).-
sub.sR.sup.83,
--(CH.sub.2).sub.pNR.sup.86C(O)(CH.sub.2).sub.q(CH.sub.2CH.sub.2O).sub.sR-
.sup.85,
--(CH.sub.2).sub.pNR.sup.86C(O)O(CH.sub.2).sub.q(CH.sub.2CH.sub.2-
O).sub.sR.sup.87, --(CH.sub.2).sub.pOC(O)NR.sup.88
(CH.sub.2).sub.q(CH.sub.2CH.sub.2O).sub.sR.sup.89, or any
combination thereof. Each of R.sup.81 to R.sup.89 is independently
--H or --CH.sub.3.
[0031] (AA) is a polypeptide chain that includes one or more
natural or unnatural .alpha.-amino acids linked together by peptide
bonds. Moreover, (PS) is a sulfated or non-sulfated polysaccharide
chain comprising one or more monosaccharide units connected by
glycosidic linkages.
[0032] Still referring to pyrazine derivatives of Formulas I and
II, each of `a`, `d`, `g`, `i`, `l`, and `q` is independently 0, 1,
2, 3, 4, 5, 6, 7, 8, 9 or 10. In addition, each of `c`, `f`, `k`,
and `p` is independently 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10. Each of
`b` and `j` is independently 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 283
29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45,
46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62,
63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96,
97, 98, 99 or 100. Further, each of `e`, `h`, `o`, and `s` is
independently 0, 1, 2, 3, 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15,
16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32,
33, 34, 35, 36, 37, 38, 39, 40, 41, 42,43, 44, 45, 46, 47, 48, 49,
50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66,
67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83,
84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or
100. In addition, each of `m` and `n` is independently 1, 2 or
3.
[0033] With regard to pyrazine derivatives of the fifth aspect,
each of X.sup.1 and X.sup.2 may independently be --CO.sub.2R.sup.1,
--COR.sup.2, or --CONR.sup.7R.sup.9 in some embodiments. In other
embodiments, each of X.sup.1 and X.sup.2 may independently be
--CO.sub.2R.sup.1 or --CONR.sup.7R.sup.9.
[0034] Y.sup.1 and Y.sup.2 may independently be --NR.sup.48R.sup.49
or
##STR00003##
in some embodiments. For instance, in some embodiments each of
Y.sup.1 and Y.sup.2 is --NR.sup.48R.sup.49.
[0035] In some embodiments, Z.sup.1 may be --O, --NR.sup.56, --S,
--SO or --SO.sub.2. For instance, in some embodiments, Z.sup.1 may
be --O or --NR.sup.56.
[0036] In some embodiments, each of R.sup.1 to R.sup.7 may
independently be
--(CH.sub.2).sub.aNR.sup.10CONR.sup.11(CH.sub.2).sub.b(CH.sub.2CH.sub.-
2O).sub.cR.sup.20,
--(CH.sub.2).sub.aCONR.sup.14(CH.sub.2).sub.b(CH.sub.2CH.sub.2O).sub.cR.s-
up.22,
--(CH.sub.2).sub.aSO.sub.2NR.sup.15(CH.sub.2).sub.b(CH.sub.2CH.sub.-
2O).sub.cR.sup.23,
--(CH.sub.2).sub.aSO.sub.2NR.sup.16(CH.sub.2).sub.b(CH.sub.2CH.sub.2O).su-
b.cR.sup.24,
--(CH.sub.2).sub.aNR.sup.17CO(CH.sub.2).sub.b(CH.sub.2CH.sub.2O).sub.cR.s-
up.25, --(CH.sub.2).sub.aNR.sup.18CO.sub.2(CH.sub.2
).sub.b(CH.sub.2CH.sub.2O).sub.cR.sup.26, or
--(CH.sub.2).sub.aOC(O)NR.sup.19(CH.sub.2).sub.b(CH.sub.2CH.sub.2O).sub.c-
R.sup.27. For instance, in some embodiments, each of R.sup.1 to
R.sup.6 may be
--(CH.sub.2).sub.aNR.sup.10CONR.sup.11(CH.sub.2).sub.b(CH.sub.2CH.-
sub.2O).sub.cR.sup.20. In other embodiments, each of R.sup.1 to
R.sup.7 may independently be
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cNR.sup.12CSNR.-
sup.13(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.21,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cCONR.sup.14(CH-
.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.22,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cNR.sup.15SO.su-
b.2(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.23,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cSO.sub.2NR.sup-
.16(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.24,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cNR.sup.18CO.su-
b.2(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.26, or
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cOC(O)NR.sup.19-
(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.27.
[0037] In some embodiments, each of R.sup.20 to R.sup.27 may
independently be --H, --CH.sub.3,
--(CH.sub.2).sub.fNR.sup.30CSNR.sup.31(CH.sub.2).sub.g(CH.sub.2CH.sub.2O)-
.sub.hR.sup.39,--(CH.sub.2).sub.f(O)NR.sup.32(CH.sub.2).sub.g(CH.sub.2CH.s-
ub.2O).sub.hR.sup.40,
--(CH.sub.2).sub.f(O).sub.2NR.sup.33(CH.sub.2).sub.g(CH.sub.2CH.sub.2O).s-
ub.hR.sup.41,
--(CH.sub.2).sub.fNR.sup.34S(O).sub.2(CH.sub.2).sub.g(CH.sub.2CH.sub.2O).-
sub.hR.sup.42,
--(CH.sub.2).sub.fNR.sup.36C(O)O(CH.sub.2).sub.g(CH.sub.2CH.sub.2O).sub.h-
R.sup.44,
--(CH.sub.2).sub.fOC(O)NR.sup.37(CH.sub.2).sub.g(CH.sub.2CH.sub.-
2O).sub.hR.sup.45, --CO(AA), or --CONH(PS).
[0038] In some embodiments, each of R.sup.38 to R.sup.45 may
independently be --H or --CH.sub.3.
[0039] In some embodiments, R.sup.46 to R.sup.57 may independently
be --H, --(CH.sub.2).sub.cOR.sup.68,
--CH.sub.2(CHOH).sub.cR.sup.69, --CH.sub.2(CHOH).sub.cCO.sub.2H,
--(CHCO.sub.2H).sub.cCO.sub.2H,
--(CH.sub.2).sub.cNR.sup.70R.sup.71,
--CH[(CH.sub.2).sub.fNH.sub.2].sub.cCO.sub.2H,
--CH[(CH.sub.2).sub.fNH.sub.2].sub.cCH.sub.2OH,
--CH.sub.2(CHNH.sub.2).sub.cCH.sub.2NR.sup.72R.sup.73,
--(CH.sub.2CH.sub.2O).sub.eR.sup.74,
--(CH.sub.2).sub.cCO(CH.sub.2CH.sub.2O).sub.eR.sup.75,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.58C(O)N-
.sup.59(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.76,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.60C(S)N-
R.sup.61(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.77,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kC(O)NR.sup.62(-
CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.78,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kS(O).sub.2NR.s-
up.63(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.79,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.64S(O).-
sub.2(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.80,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.65C(O)(-
CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.81,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.66C(O)O-
(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.82,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kOC(O)NR.sup.67-
(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.83,
--(CH.sub.2).sub.aSO.sub.3H, --(CH.sub.2).sub.aSO.sub.3.sup.-,
--(CH.sub.2).sub.aOSO.sub.3H, --(CH.sub.2).sub.aOSO.sub.3.sup.-,
--(CH.sub.2).sub.aNHSO.sub.3H, or
--(CH.sub.2).sub.aNHSO.sub.3.sup.-.
[0040] As stated above, (AA) is polypeptide chain including one or
more natural or unnatural .alpha.-amino acids linked together by
peptide bonds. The polypeptide chain (AA) may be a homopolypeptide
chain or a heteropolypeptide chain, and may be any appropriate
length. For instance, in some embodiments, the polypeptide chain
may include 1 to 100 .alpha.-amino acid(s), 1 to 90 .alpha.-amino
acid(s), 1 to 80 .alpha.-amino acid(s), 1 to 70 .alpha.-amino
acid(s), 1 to 60 .alpha.-amino acid(s), 1 to 50 .alpha.-amino
acid(s), 1 to 40 .alpha.-amino acid(s), 1 to 30 .alpha.-amino
acid(s), 1 to 20 .alpha.-amino acid(s), or even 1 to 10
.alpha.-amino acid(s). In some embodiments, the .alpha.-amino acids
of the polypeptide chain (AA) are selected from aspartic acid,
asparigine, arginine, histidine, lysine, glutamic acid, glutamine,
serine, and homoserine. In some embodiments, the .alpha.-amino
acids of the polypeptide chain (AA) are selected from aspartic
acid, glutamic acid, serine, and homoserine. In some embodiments,
the polypeptide chain (AA) refers to a single amino (e.g., either
aspartic acid or serine).
[0041] As stated above, (PS) is a sulfated or non-sulfated
polysaccharide chain including one or more monosaccharide units
connected by glycosidic linkages. The polysaccharide chain (PS) may
be any appropriate length. For instance, in some embodiments, the
polysaccharide chain may include 1 to 100 monosaccharide unit(s), 1
to 90 monosaccharide unit(s), 1 to 80 monosaccharide unit(s), 1 to
70 monosaccharide unit(s), 1 to 60 monosaccharide unit(s), 1 to 50
monosaccharide unit(s), 1 to 40 monosaccharide unit(s), 1 to 30
monosaccharide unit(s), 1 to 20 monosaccharide unit(s), or even 1
to 10 monosaccharide unit(s). In some embodiments, the
polysaccharide chain (PS) is a homopolysaccharide chain consisting
of either pentose or hexose monosaccharide units. In other
embodiments, the polysaccharide chain (PS) is a
heteropolysaccharide chain consisting of one or both pentose and
hexose monosaccharide units. In some embodiments, the
monosaccharide units of the polysaccharide chain (PS) are selected
from the group consisting of glucose, fructose, mannose, xylose and
ribose. In some embodiments, the polysaccharide chain (PS) refers
to a single monosaccharide unit (e.g., either glucose or
fructose).
[0042] Still referring to pyrazine derivatives of Formulas I and
II, in some embodiments, each of `a`, `d`, `i`, `l`, and `q` may
independently be 1, 2, 3, 4, 5 or 6. Each of `e`, `h`, `o`, and `s`
may independently be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19 or 20 in some embodiments. Similarly, in some
embodiments, each of `b` and `j` may independently be 0, 1, 2, 3,
4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20. In
some embodiments, each of `m` and `n` may independently be 1 or
2.
[0043] Any of the pyrazine derivatives described above may exhibit
any appropriate molecular weight. For instance, in some
embodiments, a pyrazine derivative of the invention may have a
molecular weight of no more than about 20000. In other embodiments,
a pyrazine derivative of the invention may have a molecular weight
of no more than about 15000, 14000, 13000, 12000, 11000, 10000,
9000, 8000, 7000, 6000, 5000, 4500, 4000, 3500, 3000, 2500, 2000,
1500, 1000, 900, 800, 700, 600, 500, 400, 300, 200, or even 100.
Other embodiments may have molecular weights that are greater than
about 20000.
[0044] Yet a sixth aspect of the invention is directed to methods
of using pyrazine derivatives described herein. In such methods, a
pyrazine derivative is administered to a patient and utilized in a
medical photodiagnostic and/or imaging procedure (e.g., assessing
renal function).
[0045] Still a seventh aspect of the invention is directed to
pharmaceutically acceptable compositions, each of which includes
one or more pyrazine derivatives disclosed herein. The phrase
"pharmaceutically acceptable" herein refers substances that are,
within the scope of sound medical judgment, suitable for use in
contact with relevant tissues of humans and animals without undue
toxicity, irritation, allergic response and the like, and are
commensurate with a reasonable benefit/risk ratio. The compositions
of this seventh aspect may include one or more appropriate
excipients such as, but not limited to, suitable diluents,
preservatives, solubilizers, emulsifiers, adjuvant and/or carriers.
One example of a composition of this aspect may include at least
one pyrazine derivative of Formula I and/or at least one pyrazine
derivative of Formula II.
[0046] Yet an eighth aspect of the invention is directed to methods
of determining renal function using pyrazine derivatives such as
those described above (e.g., with regard to Formulas I and II). In
these methods, an effective amount of a pyrazine derivative is
administered into the body of a patient (e.g., a mammal such as a
human or animal subject). Incidentally, an "effective amount"
herein generally refers to an amount of pyrazine derivative that is
sufficient to enable renal clearance to be analyzed. The pyrazine
derivative in the body of the patient is exposed to at least one of
visible and near infrared light. Due to this exposure of the
pyrazine derivative to the visible and/or infrared light, the
pyrazine derivative emanates spectral energy that may be detected
by appropriate detection equipment. This spectral energy emanating
from the pyrazine derivative may be detected using an appropriate
detection mechanism such as an invasive or non-invasive optical
probe. Herein, "emanating" or the like refers to spectral energy
that is emitted and/or fluoresced from a pyrazine derivative. Renal
function may be determined based on the spectral energy that is
detected. For example, an initial amount of the amount of pyrazine
derivative present in the body of a patient may be determined by a
magnitude/intensity of light emanated from the pyrazine derivative
that is detected (e.g., in the bloodstream). As the pyrazine
derivative is cleared from the body, the magnitude/intensity of
detected light generally diminishes. Accordingly, a rate at which
this magnitude of detected light diminishes may be correlated to a
renal clearance rate of the patient. This detection may be done
periodically or in substantially real time (providing a
substantially continuous monitoring of renal function). Indeed,
methods of the present invention enable renal function/clearance to
be determined via detecting one or both a change and a rate of
change of the detected magnitude of spectral energy (indicative of
an amount of the pyrazine derivative that has not been cleared)
from the portion of the pyrazine derivative that remains in the
body. While this aspect has been described with regard to use of a
single pyrazine derivative of the invention, it should be noted
that some embodiments of this aspect include the use of
compositions of the invention that may include one or more pyrazine
derivatives disclosed herein.
[0047] Yet a ninth aspect of the invention is directed to a method
for producing pyrazine derivatives. In this method, an
aminopyrazine compound and a carbonyl compound are combined in the
presence of a reducing agent.
[0048] In some embodiments of the method, the aminopyrazine
compound is a diaminopyrazine, and the pyrazine derivative is an
N,N'-alkylated diaminopyrazine.
[0049] Some embodiments of the method may include the aminopyrazine
compound, the carbonyl compound, and a solvent being combined in
the presence of the reducing agent.
[0050] In some embodiments of the method, the aminopyrazine
compound and a carbonyl compound may be combined at a temperature
between about -20.degree. and about 50.degree. C. For instance, in
some embodiments, this combining may occur at a temperature between
about -5.degree. and about 30.degree. C.
[0051] The carbonyl compound used in the method may be any
appropriate carbonyl compound. For instance, in some embodiments,
the carbonyl compound may be of Formula III below.
##STR00004##
[0052] In Formula III, each of R.sup.1 and R.sup.2 is independently
hydrogen, C.sub.1-C.sub.10 alkyl, C.sub.5-C.sub.20 aralkyl,
C.sub.1-C.sub.20 hydroxyalkyl, C.sub.2-C.sub.20 polyhydroxyalkyl,
--(CH.sub.2).sub.nCO.sub.2R.sup.3,
--(CH.sub.2CH.sub.2O).sub.mR.sup.4, or mono- or poly-saccharide
containing 1 to 50 units.
[0053] Referring to R.sup.1 and R.sup.2 of Formula III, m and n may
be any appropriate integers. For instance, in some embodiments,
each of m and n is independently 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28,
29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45,
46, 47, 48, 49 or 50. In some embodiments, each of m and n may
independently be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30. In
other embodiments, m and n may independently be 1, 2, 3, 4, 5, 6,
7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20. In yet other
embodiments, m and n may independently be 1, 2, 3, 4, 5, 6, 7, 8, 9
or 10.
[0054] Still referring to R.sup.1 and R.sup.2 of Formula III, each
occurrence of R.sup.3 and R.sup.4 is independently hydrogen,
C.sub.1-C.sub.10 alkyl, C.sub.5-C.sub.20 aralkyl, C.sub.1-C.sub.10
acyl, C.sub.1-C.sub.20 hydroxyalkyl, C.sub.2-C.sub.20
polyhydroxyalkyl, or mono- or poly-saccharide containing 1 to 50
units. For instance, in some embodiments, each of R.sup.3 and
R.sup.4 is independently hydrogen, C.sub.1-C.sub.10 alkyl,
C.sub.1-C.sub.20 hydroxyalkyl, or C.sub.2-C.sub.20
polyhydroxyalkyl.
[0055] The aminopyrazine compound utilized in the method may be any
appropriate aminopyrazine compound. For instance, the aminopyrazine
compound utilized may be a compound of the following Formula IV or
V below.
##STR00005##
[0056] With regard to Formulas IV and V above, each X and Y is
independently hydrogen, C.sub.1-C.sub.10 alkyl, --OR.sup.5,
--SR.sup.6, --NR.sup.7R.sup.8, --N(R.sup.9)COR.sup.10, halo,
trihaloakyl, --CN, --NO.sub.2, --CO-Z-R.sup.11, --SOR.sup.12,
--SO.sub.2R.sup.13, --SO.sub.2OR.sup.14, or
--PO.sub.3R.sup.15R.sup.16. Z is a single bond, --O--,
--NR.sup.17--, --NH(CH.sub.2).sub.pNH--, --NH(CH.sub.2).sub.pO--,
--NH(CH.sub.2).sub.pCO--, --NH(CH.sub.2).sub.pNHCO--,
--NH(CH.sub.2).sub.pCONH--, --NH(CH.sub.2).sub.pNHCONH--,
--NH(CH.sub.2).sub.pNHCSNH--, or --NH(CH.sub.2).sub.pNHCO.sub.2--.
Each of R.sup.5 to R.sup.17 is independently hydrogen,
C.sub.1-C.sub.10 alkyl, C.sub.5-C.sub.20 aralkyl, C.sub.1-C.sub.10
acyl, C.sub.1-C.sub.20 hydroxyalkyl, C.sub.2-C.sub.20
polyhydroxyalkyl, --(CH.sub.2CH.sub.2O).sub.qR.sup.18, or mono- or
poly-saccharide containing 1 to 50 units. R.sup.18 is hydrogen,
C.sub.1-C.sub.10 alkyl, C.sub.5-C.sub.20 aralkyl, C.sub.1-C.sub.10
acyl, C.sub.1-C.sub.20 hydroxyalkyl, C.sub.2-C.sub.20
polyhydroxyalkyl, or mono- or poly-saccharide containing 1 to 50
units. The integer p 0, 1, 2, 3, 4, 5 or 6. Further, the integer q
is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50.
[0057] In some compounds of Formulas IV and V above, each of X and
Y may be --CN in some embodiments and --CO-Z-R.sup.11 in other
embodiments. In embodiments of compounds of Formulas IV and V that
include R.sup.11, R.sup.11 of some embodiments may be hydrogen,
C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.20 hydroxyalkyl, or
C.sub.2-C.sub.20 polyhydroxyalkyl. When each of X and Y is
--CO-Z-R.sup.11, Z may be --NR.sup.17-- in some embodiments,
--NH(CH.sub.2).sub.pNH-- in other embodiments, and
--NH(CH.sub.2).sub.pCO-- in other embodiments. In the case that Z
is --NR.sup.17--, R.sup.17 of some embodiments may be hydrogen or
C.sub.1-C.sub.10 alkyl. In the case that Z is either
NH(CH.sub.2).sub.pNH-- or --NH(CH.sub.2).sub.pCO--, the integer p
of some embodiments may be 0, 1, 2, 3 or 4.
[0058] The reducing agent utilized in the method may be any
appropriate reducing agent. For instance, in some embodiments, the
reducing agent is ammonium formate, diimide, Zn/HCl, sodium
triacetoxyborohydride, sodium borohydride, pyridine/borane, lithium
aluminium hydride, lithium borohydride, sodium cyanoborohydride,
sodium amalgam, H.sub.2/Pd/C, H.sub.2/Pt/C, H.sub.2/Rh/C,
H.sub.2/Raney.RTM. Nickel, or any combination thereof. In some
embodiments, the reducing agent includes or is sodium
triacetoxyborohydride. In some embodiments, the reducing agent
includes or is sodium cyanoborohydride.
[0059] In the case that a solvent is utilized in the method, the
solvent may be any appropriate solvent such as, for example, water,
C.sub.1-C.sub.8 alcohol, C.sub.1-C.sub.8 ether, C.sub.1-C.sub.8
ester, dimethyl formamide, dimethyl acetamide, acetic acid,
trifluoroacetic acid, dimethyl sulfoxide, or any combination
thereof. In some embodiments, the solvent may be methanol, ethanol,
isopropyl alcohol, tetrahydrofuran, dioxane, glyme, dimethyl
formamide, dimethyl sulfoxide, or any combination thereof.
[0060] A related area of the present invention is directed pyrazine
derivatives that are made utilizing a method described herein.
Pyrazine derivatives made using the method described herein may be
utilized in a number of appropriate processes and procedures (e.g.,
medical procedures). For instance, pyrazine derivatives made using
a method described herein may be utilized in assessing renal
function of a medical patient and/or as intermediates in processes
for manufacturing pyrazine derivatives and/or compositions that
include pyrazine derivatives (e.g., for use in assessing renal
function of medical patients).
[0061] These and other features, aspects and advantages of the
present teachings will become better understood with reference to
the following description, examples and appended claims.
[0062] Those of skill in the art will understand that the drawings,
described below, are for illustrative purposes only. The drawings
are not intended to limit the scope of the present teachings in any
way.
BRIEF DESCRIPTION OF THE FIGURES
[0063] FIG. 1. A block diagram of an assembly for assessing renal
function.
[0064] FIG. 2. Illustration of a clearance curve of compound 18
(Formula VI).
[0065] FIG. 3. Comparison of compound 18 and an iothalamate
standard.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
[0066] Abbreviations and Definitions
[0067] To facilitate understanding of the invention, a number of
terms and abbreviations as used herein are defined below as
follows:
[0068] Pharmacokinetic: As used herein, the term "pharmacokinetic"
refers to how a compound is absorbed, distributed, metabolized, and
eliminated by the body.
[0069] Half-life: As used herein, the term "half-life" refers to
the time required for the amount of a compound in the body to fall
by half.
[0070] Clearance: As used herein, the term "clearance" describes
the efficiency of elimination of a compound from the body.
[0071] A, An, and The: As used herein, the articles "a", "an", and
"the" are intended to mean that there are one or more of something
that the article(s) introduce(s).
[0072] Comprising, Including, and Having: As used herein, the terms
"comprising", "including", and "having" are intended to be
inclusive and mean that there may be additional items (e.g.,
substituents, groups, elements, steps, etc.) other than that
mentioned.
[0073] Pyrazine Derivatives, Methods of Using Pyrazine Derivatives,
and Preparing Pyrazine Derivatives
[0074] The present invention provides compounds that can be
detected in vivo and used in a number of medical procedures,
including renal function monitoring. The compounds can be pyrazine
derivatives having a pyrazine ring that can have a substituent
bonded to a carbon of the pyrazine ring. The carbon of the pyrazine
ring can have a substituent bonded thereto that includes a group
selected from urea, amide, sulfonamide, thiourea, carbamate, or any
combination thereof. Without being bound by a particular theory,
the pyrazine derivatives of the present invention are designed to
be hydrophilic and/or have rigid functionality which it thought to
allow for rapid renal clearance while also providing
pharmacokinetic properties for monitoring renal function. One of
skill in the art will recognize that other uses are contemplated
herein. For example, pyrazine derivatives of the present invention
can be used in accordance with the methods provided in patent
application PCT/US2006/039732, incorporated herein by reference in
its entirety.
[0075] Molecules absorbing, emitting, and/or scattering in the
visible, NIR, and/or long-wavelength (TV-A, >300 nm) region of
the electromagnetic spectrum are useful for optical measurement.
The high sensitivity associated with fluorescence phenomenon
permits quantification without the negative effects of
radioactivity or ionizing radiation. Pyrazine derivatives of
general structures A and B below are one of the few classes of
small molecules having desirable photophysical properties for
biomedical optical applications.
##STR00006##
These compounds have low molecular weight fluorescent scaffold
systems with surprisingly bright emissions in the yellow-to-red
region of the electromagnetic spectrum. In particular, pyrazine
derivative A that contains electron donating groups (EDG) in the
2,5 positions and electron withdrawing groups (EWG) in the 3,6
positions are shown to absorb and emit in the visible region with a
large Stokes shift.[15-18] These properties allow flexibility in
both tuning a molecule to a desired wavelength and introducing a
variety of substituents to improve clearance properties
[0076] Molecules designed for renal monitoring applications must be
cleared from the body via the kidneys. Hydrophilic, anionic
substances are generally capable of being excreted by the
kidneys.[19] Renal clearance typically occurs via two pathways:
glomerular filtration and tubular secretion. Tubular secretion is
characterized as an active transport process, and substances
clearing via this pathway exhibit specific properties with respect
to size, charge and lipophilicity. Most of the substances that pass
through the kidneys are filtered through the glomerulus (a small
intertwined group of capillaries in the malpighian body of the
kidney). In general, molecules which are highly hydrophilic and
small (creatinine, molecular weight=113) to moderately sized
(inulin, molecular weight .about.5500) are rapidly cleared from
systemic circulation by glomerular filtration.[20]
[0077] In addition to these properties, the ideal GFR agent should
not be reabsorbed nor secreted by the renal tubule, exhibit
negligible binding to plasma proteins, and have very low toxicity.
Optical probes that satisfy all of these requirements strike a
balance between photophysical properties and the molecular size and
hydrophilicity of the compound.
[0078] To achieve these goals, polyethylene glycol (PEG) units can
be incorporated with the pyrazine core. As referred to herein, a
"PEG unit" means a CH.sub.2CH.sub.2O unit. PEG units are typically
components of highly soluble oligomers and polymers of ethylene
glycol. Further, they tend to be highly biocompatible,
non-immunogenic, and non-toxic. PEG polymers have been used
primarily to modify therapeutic proteins for enhancement of their
pharmacokinetic performance in vivo. PEG polymers are usually of
high molecular weight (20-500 kDal) and may be branched or linear
chains. Pegylation is known to significantly increase the apparent
size (Stokes-Einstein radius or hydrodynamic volume) of the
conjugated drug compound. In the case of some therapeutic proteins,
the very large hydrodynamic volume of the conjugate has been shown
to slow down renal clearance and prolong pharmacokinetic half-life.
Ikada has studied the biodistribution of PEG polymers after i.v.
administration and found that the terminal half-life in the
circulation extended from 18 min to 1 day as the PEG molecular
weight increased from 6,000 to 190,000.[21] The lower end of this
range is acceptable for a renal function agent. Lower molecular
weight PEG polymers (at least <6,000) are known to be filtered
by the glomerulus and not reabsorbed by the renal tubules.[21]
[0079] Additionally, inserting rigidifying functional groups
between the PEG units can further improve the pharmacokinetic
performance of the renal monitoring agents. These rigidifying
groups include urea, amide, sulfonamide, thiourea, carbamate, or
any combination thereof. Such groups are good hydrogen bond donors
and acceptors and have partial double bond character which
restricts free rotation about the bond and confers a planar
geometry to the functional group. Without being bound by a
particular theory, it is believed that these rigid groups enhance
the pharmacokinetic properties of the renal agents by increasing
the apparent volume and modulating aggregation of the resulting
pyrazine derivatives.
[0080] In one aspect of the present invention, pyrazine derivatives
can have at least one occurrence of a urea, amide, sulfonamide,
thiourea, carbamate, or any combination thereof. This "occurrence"
is typically separated from the carbon of the pyrazine ring to
which the substituent is bonded by at least two atoms. For example,
the substituent may include one of the aforementioned groups that
is bonded directly to the carbon as long as the substituent also
has at least one occurrence of one of the aforementioned groups
that is separated from the carbon of the pyrazine ring to which the
substituent is bonded by at least two atoms.
[0081] The occurrence of the urea, amide, sulfonamide, thiourea,
carbamate, or any combination thereof, may be separated from the
carbon of the pyrazine ring to which the substituent is bonded by
other appropriate atom spacings. For instance, at least one
occurrence of the substituent group can be separated from the
carbon of the pyrazine ring to which the substituent is bonded by
at least three atoms. La other embodiments, at least one occurrence
of an aforementioned group can be separated from the carbon of the
pyrazine ring to which the substituent is bonded by at least four
atoms. In still other embodiments, at least one occurrence of an
aforementioned group can be separated from the carbon of the
pyrazine ring to which the substituent is bonded by at least five
atoms. In other embodiments, at least one occurrence of an
aforementioned group can be separated from the carbon of the
pyrazine ring to which the substituent is bonded by at least six
atoms.
[0082] In some embodiments, each occurrence of any of the listed
groups may be separated from the carbon of the pyrazine ring to
which the substituent is bonded by at least two atoms. In other
words, no portion of a urea, amide, sulfonamide, thiourea,
carbamate, or any combination thereof is located within two atoms
of the carbon of the pyrazine ring to which the substituent is
bonded in these embodiments. In some of these embodiments, each
occurrence of the group may be separated from the carbon of the
pyrazine ring to which the substituent is bonded by at least three,
at least four, at least five, or at least six atoms.
[0083] In some embodiments, each of the four carbons of the
pyrazine ring has a substituent bonded thereto. In such
embodiments, each occurrence of any of the listed groups that is a
component of one or more of the four substituents may be separated
from the carbon of the pyrazine ring to which the substituent is
bonded by at least two atoms. In other embodiments, each occurrence
of an aforementioned group of any of the four substituents may be
separated from the carbon of the pyrazine ring to which the
substituent is bonded by at least three, at least four, at least
five, or even at least six atoms.
[0084] In some embodiments, a first carbon of the pyrazine ring has
a first substituent bonded thereto that includes a first group
selected from urea, amide, sulfonamide, thiourea, carbamate, and
any combination thereof. Further, a second carbon of the pyrazine
ring has a second substituent bonded thereto that includes a second
group selected from urea, amide, sulfonamide, thiourea, carbamate,
and any combination thereof. In such embodiments, the first group
is separated from the first carbon of the pyrazine ring by at least
two atoms, and the second group is separated from the second carbon
of the pyrazine ring by at least two atoms. The first group may be
the same as or different from the second group. For instance, in
the case that the first group is the same as the second group, the
first group and the second may each be an amide. As another
example, the first group and the second group may each be a urea.
In some embodiments, the first substituent that is bonded to the
first carbon of the pyrazine ring may be the same as or different
from the second substituent. The first carbon and the second carbon
may be located in any appropriate positions along the pyrazine
ring. For instance, in some embodiments, the first carbon of the
pyrazine ring is para to the second carbon of the pyrazine ring. In
other embodiments, the first carbon of the pyrazine ring is meta to
the second carbon of the pyrazine ring.
[0085] In embodiments having a first substituent that is bonded to
a first carbon of the pyrazine ring and a second substituent that
is bonded to a second carbon of the pyrazine ring, the first and
second substituents may include any of a number of other
appropriate groups besides each including at least one of the
groups mentioned above (e.g., urea, amide, sulfonamide, thiourea,
carbamate, and/or any combination thereof). For instance, in some
embodiments, at least one of the first and second substituents may
include at least one PEG unit (e.g., a plurality of PEG units). In
some embodiments, each of the first substituent and second
substituent comprises at least one PEG unit. For example, the first
substituent may include a plurality of PEG units, and the second
substituent may also include a plurality of PEG units.
[0086] Another aspect of the invention is directed to pyrazine
derivatives, each of which includes a pyrazine ring that comprises
a first carbon, a second carbon, a third carbon, and a fourth
carbon. The first carbon has a first substituent bonded thereto,
the second carbon has a second substituent bonded thereto, the
third carbon has a third substituent bonded thereto, and the fourth
carbon has a fourth substituent bonded thereto. Each of the first,
second, third, and fourth substituents includes a urea, amide,
sulfonamide, thiourea, carbamate, or any combination thereof.
[0087] In some embodiments, the structure of a given substituent
may be the same as or different from one or more other substituents
of the pyrazine derivative. For instance, in some embodiments, the
first and second substituents are the same, and the third and
fourth substituents are the same but different from the first and
second substituents. In such embodiments, the first and second
carbons may be para to each other (which means the third and fourth
carbons would also be para to each other), or the first and second
carbons may be meta to each other (which means the third and fourth
carbons would also be meta to each other).
[0088] In some embodiments, each of the first substituent and
second substituent includes an amide. For instance, each of the
first, second, third, and fourth substituents includes an
amide.
[0089] The pyrazine derivative can include at least two of the
first, second, third, and fourth substituents having at least one
PEG unit. For instance, each of the first and second substituents
can include at least one PEG unit (e.g., a plurality of PEG units).
As another example, each of the first, second, third, and fourth
substituents can include at least one PEG unit (e.g., a plurality
of PEG units).
[0090] In yet another aspect of the present invention, a pyrazine
derivative can include a pyrazine ring in which a carbon of the
pyrazine ring has a substituent bonded thereto that includes a urea
group. The urea group is separated from the carbon of the pyrazine
ring to which the substituent is bonded by at least two atoms. For
instance, the substituent may include one urea that is bonded
directly to the carbon of the pyrazine ring as long as the
substituent also includes at least one other urea that is separated
from the carbon of the pyrazine ring to which the substituent is
bonded by at least two atoms. As another example, one substituent
may include a urea that is bonded directly to one carbon of the
pyrazine ring, and another substituent may include another urea
that is separated from the respective carbon of the pyrazine ring
to which that substituent is bonded by at least two atoms.
[0091] In various embodiments, at least one occurrence of a urea
group may be separated from the carbon of the pyrazine ring to
which the substituent is bonded by other appropriate atom spacings.
For instance, in some embodiments, at least one occurrence of a
urea group is separated from the carbon of the pyrazine ring to
which the corresponding substituent is bonded by at least three
atoms. In other embodiments, at least one occurrence of a urea
group is separated from the carbon of the pyrazine ring to which
the corresponding substituent is bonded by at least four atoms. In
still other embodiments, at least one occurrence of a urea group is
separated from the carbon of the pyrazine ring to which the
corresponding substituent is bonded by at least five atoms. And in
even other embodiments, at least one occurrence of a urea group is
separated from the carbon of the pyrazine ring to which the
corresponding substituent is bonded by at least six atoms.
[0092] In some embodiments, the substituent includes multiple
occurrences of urea groups, and each occurrence of a urea group is
separated from the carbon of the pyrazine ring to which the
substituent is bonded by at least two atoms. In other words, in
these embodiments, no portion of a urea group is located within two
atoms of the carbon (of the pyrazine ring) to which the substituent
is bonded. In some substituents that include multiple occurrences
of urea groups, each occurrence of a urea group may be separated
from the carbon of the pyrazine ring to which the substituent is
bonded by at least three, at least four, at least five, or even at
least six atoms.
[0093] In some embodiments, each of the four carbons of the
pyrazine ring has a substituent bonded thereto. In such
embodiments, each occurrence of a urea group of any of the four
substituents may be separated from the carbon of the pyrazine ring
to which the substituent is bonded by at least two atoms. In other
embodiments, each occurrence of a urea of any of the four
substituents may be separated from the carbon of the pyrazine ring
to which the substituent is bonded by at least three, at least
four, at least five, or even at least six atoms.
[0094] In various embodiments, the substituent(s) may include any
of a number of other appropriate groups besides at least one urea.
For instance, in some embodiments, the substituent that includes
the urea may also include at least one PEG unit (e.g., a plurality
of PEG units). In some embodiments, each of a plurality (e.g., two,
three, or four) of substituents, each of which is bound to a
different carbon of the pyrazine ring, may include at least one PEG
unit. For example, in some embodiments, a first substituent bound
to a first carbon of the pyrazine ring may include a urea and
plurality of PEG units, and a second substituent bound to a second
carbon of the pyrazine ring may also include a urea and a plurality
of PEG units. In such embodiments, the first and second carbons may
be either meta or para to each other. In other embodiments, a first
substituent bound to a first carbon of the pyrazine ring may
include a urea and plurality of PEG units, and a second substituent
bound to a second carbon of the pyrazine ring may not include a
urea but may include one or more PEG units.
[0095] In yet another aspect of the present invention, a carbon of
the pyrazine ring has a substituent bonded thereto that includes an
amide group. This amide group is separated from the carbon of the
pyrazine ring to which the substituent is bonded by at least two
atoms. So, for example, the substituent may include one amide that
is bonded directly to the carbon of the pyrazine ring as long as
the substituent also includes at least one other amide that is
separated from the carbon of the pyrazine ring to which the
substituent is bonded by at least two atoms. As another example,
one substituent may include an amide that is bonded directly to one
carbon of the pyrazine ring, and another substituent may include
another amide that is separated from the respective carbon of the
pyrazine ring to which that substituent is bonded by at least two
atoms.
[0096] In various embodiments, at least one occurrence of an amide
group may be separated from the carbon of the pyrazine ring to
which the substituent is bonded by other appropriate atom spacings.
For instance, at least one occurrence of an amide group is
separated from the carbon of the pyrazine ring to which the
corresponding substituent is bonded by at least three atoms. In
other embodiments, at least one occurrence of an amide group is
separated from the carbon of the pyrazine ring to which the
corresponding substituent is bonded by at least four atoms. In
still other embodiments, at least one occurrence of an amide group
is separated from the carbon of the pyrazine ring to which the
corresponding substituent is bonded by at least five atoms. In
other embodiments, at least one occurrence of an amide group is
separated from the carbon of the pyrazine ring to which the
corresponding substituent is bonded by at least six atoms.
[0097] In some embodiments, the substituent includes multiple
occurrences of amide groups, and each occurrence of an amide group
is separated from the carbon of the pyrazine ring to which the
substituent is bonded by at least two atoms. In other words, in
these embodiments, no portion of an amide group is located within
two atoms of the carbon (of the pyrazine ring) to which the
substituent is bonded. In some substituents that include multiple
occurrences of amide groups, each occurrence of an amide group may
be separated from the carbon of the pyrazine ring to which the
substituent is bonded by at least three, at least four, at least
five, or even at least six atoms.
[0098] In some embodiments, each of the four carbons of the
pyrazine ring has a substituent bonded thereto. In such
embodiments, each occurrence of an amide group of any of the four
substituents may be separated from the carbon of the pyrazine ring
to which the substituent is bonded by at least two atoms. In other
embodiments, each occurrence of an amide of any of the four
substituents may be separated from the carbon of the pyrazine ring
to which the substituent is bonded by at least three, at least
four, at least five, or even at least six atoms.
[0099] The substituent(s) may include any of a number of other
appropriate groups besides at least one amide. For instance, in
some embodiments, the substituent that includes the amide may also
include at least one PEG unit (e.g., a plurality of PEG units). In
some embodiments, each of a plurality (e.g., two, three, or four)
of substituents, each of which is bound to a different carbon of
the pyrazine ring, may include at least one PEG unit. For example,
in some embodiments, a first substituent bound to a first carbon of
the pyrazine ring may include an amide and plurality of PEG units,
and a second substituent bound to a second carbon of the pyrazine
ring may also include an amide and a plurality of PEG units. In
such embodiments, the first and second carbons may be either meta
or para to each other. In other embodiments, a first substituent
bound to a first carbon of the pyrazine ring may include an amide
and plurality of PEG units, and a second substituent bound to a
second carbon of the pyrazine ring may not include an amide but may
include one or more PEG units.
[0100] Yet another aspect of the present invention is directed to
pyrazine derivatives of Formulas I and II below.
##STR00007##
[0101] With regard to Formulas I and II, each of X.sup.1 and
X.sup.2 can independently be --CO.sub.2R.sup.1, --COR.sup.2,
--SOR.sup.3, --SO.sub.2R.sup.4, --SO.sub.2OR.sup.5,
--PO.sub.3R.sup.6R.sup.8, or --CONR.sup.7R.sup.9. Each of R.sup.1
to R.sup.7 can independently be
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cNR.sup.10CONR.-
sup.11(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.20,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cNR.sup.12CSNR.-
sup.13(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.21,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cCONR.sup.14(CH-
.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.22,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cNR.sup.15SO.su-
b.2(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.cR.sup.23,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cSO.sub.2NR.sup-
.16(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.24,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cNR.sup.17CO(CH-
.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.25,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cNR.sup.18CO.su-
b.2(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.26,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cOC(O)NR.sup.19-
(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.cR.sup.27, or any
combination thereof Each of R.sup.8 to R.sup.19 can independently
be --H or --CH.sub.3. Each of R.sup.20 to R.sup.27 can
independently be --H, --CH.sub.3,
--(CH.sub.2).sub.fNR.sup.28C(O)NR.sup.29(CH.sub.2).sub.g(CH.sub.2CH.sub.2-
O).sub.hR.sup.38,
--(CH.sub.2).sub.fNR.sup.30CSNR.sup.31(CH.sub.2).sub.g(CH.sub.2CH.sub.2O)-
.sub.hR.sup.39,
--(CH.sub.2).sub.fC(O)NR.sup.32(CH.sub.2).sub.g(CH.sub.2CH.sub.2O).sub.hR-
.sup.40,
--(CH.sub.2).sub.fS(O).sub.2N.sup.33(CH.sub.2).sub.g(CH.sub.2CH.s-
ub.2O).sub.hR.sup.41,
--(CH.sub.2).sub.fNR.sup.34S(O).sub.2(CH.sub.2).sub.g(CH.sub.2CH.sub.2O).-
sub.hR.sup.42,
--(CH.sub.2).sub.fNR.sup.35C(O)(CH.sub.2).sub.g(CH.sub.2CH.sub.2O).sub.hR-
.sup.43,
--(CH.sub.2).sub.fNR.sup.36C(O)O(CH.sub.2).sub.g(CH.sub.2CH.sub.2-
O).sub.hR.sup.44,
--(CH.sub.2).sub.fOC(O)NR.sup.37(CH.sub.2).sub.g(CH.sub.2CH.sub.2O).sub.h-
R.sup.45, --CO(AA), --CONH(PS), or any combination thereof. Each of
R.sup.28 to R.sup.37 can independently be --H or --CH.sub.3. Each
of R.sup.38 to R.sup.45 can independently be --H, --CH.sub.3,
--CO(AA) or --CONH(PS).
[0102] Still referring to pyrazine derivatives of Formulas I and II
above, each of Y.sup.1 and Y.sup.2 can independently be
--OR.sup.46, --SR.sup.47, --NR.sup.48R.sup.49,
--N(R.sup.50)COR.sup.51, --P(R.sup.52).sub.3, --P(OR.sup.53).sub.3,
or
##STR00008##
Z.sup.1 can be a single bond, --CR.sup.54R.sup.55, --O,
--NR.sup.56, --NCOR.sup.57, --S, --SO, or --SO.sub.2. Each of
R.sup.46 to R.sup.57 can independently be --H,
--(CH.sub.2).sub.cOR.sup.68, --CH.sub.2(CHOH).sub.cR.sup.69,
--CH.sub.2(CHOH).sub.cCO.sub.2H, --(CHCO.sub.2H).sub.cCO.sub.2H,
--(CH.sub.2).sub.cNR.sup.70R.sup.71,
--CH[(CH.sub.2).sub.fNH.sub.2].sub.eCO.sub.2H,
--CH[(CH.sub.2).sub.fNH.sub.2].sub.cCH.sub.2OH,
--CH.sub.2(CHNH.sub.2).sub.cCH.sub.2NR.sup.72R.sup.73,
--(CH.sub.2CH.sub.2O).sub.eR.sup.74,
--(CH.sub.2).sub.cCO(CH.sub.2CH.sub.2O).sub.eR.sup.75,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.58C(O)N-
R.sup.59(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.76,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.60C(S)N-
R.sup.61(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.77,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kC(O)NR.sup.62(-
CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.78,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kS(O).sub.2NR.s-
up.63(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.79,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.64
S(O).sub.2(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.80,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.65C(O)(-
CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.81,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.66C(O)O-
(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.82,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kOC
(O)NR.sup.67(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.83,--(CH.sub.2-
).sub.aSO.sub.3H, --(CH.sub.2).sub.aSO.sub.3.sup.-,
--(CH.sub.2).sub.aOSO.sub.3H, --(CH.sub.2).sub.aOSO.sub.3.sup.-,
--(CH.sub.2).sub.aNHSO.sub.3H, --(CH.sub.2).sub.aNHSO.sub.3.sup.-,
--(CH.sub.2).sub.aPO.sub.3H.sub.2,
--(CH.sub.2).sub.aPO.sub.3H.sup.-,
--(CH.sub.2).sub.aPO.sub.3.sup.=,
--(CH.sub.2).sub.aOPO.sub.3H.sub.2,
--(CH.sub.2).sub.aOPO.sub.3H.sup.-, --(CH.sub.2).sub.aOPO.sub.3, or
any combination thereof. Each of R.sup.58 to R.sup.67 can
independently be --H or --CH.sub.3. Each of R.sup.68 to R.sup.83
can independently be --H, --CH.sub.3,
--(CH.sub.2).sub.pNR.sup.81C(O)NR.sup.82(CH.sub.2).sub.q(CH.sub.2CH.sub.2-
O).sub.sR.sup.77,
--(CH.sub.2).sub.pC(O)NR.sup.83(CH.sub.2).sub.q(CH.sub.2CH.sub.2O).sub.sR-
.sup.79,
--(CH.sub.2).sub.pS(O).sub.2NR.sup.84(CH.sub.2).sub.q(CH.sub.2CH.-
sub.2O).sub.sR.sup.81,
--(CH.sub.2).sub.pNR.sup.85S(O).sub.2(CH.sub.2).sub.q(CH.sub.2CH.sub.2O).-
sub.sR.sup.83,
--(CH.sub.2).sub.pNR.sup.86C(O)(CH.sub.2).sub.q(CH.sub.2CH.sub.2O).sub.sR-
.sup.85,
--(CH.sub.2).sub.pNR.sup.86C(O)O(CH.sub.2).sub.q(CH.sub.2CH.sub.2-
O).sub.sR.sup.87,
--(CH.sub.2).sub.pOC(O)NR.sup.88(CH.sub.2)q(CH.sub.2CH.sub.2O).sub.sR.sup-
.89, or any combination thereof. Each of R.sup.81 to R.sup.89 can
independently be --H or --CH.sub.3.
[0103] (AA) is a polypeptide chain that includes one or more
natural or unnatural .alpha.-amino acids linked together by peptide
bonds. (PS) is a sulfated or non-sulfated polysaccharide chain
comprising one or more monosaccharide units connected by glycosidic
linkages.
[0104] Still referring to pyrazine derivatives of Formulas I and
III each of `a`, `d`, `g`, `i`, `l`, and `q` can independently be
0, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10. In addition, each of `c`, `f`,
`k`, and `p` can independently be 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.
Each of `b` and `j` can independently be 0, 1, 2, 3, 4, 5, 6, 7, 8,
9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,
26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42,
43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59,
60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76,
77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93,
94, 95, 96, 97, 98, 99 or 100. Further, each of `e`, `h`, `o`, and
`s` can independently be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46,
47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80,
81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97,
98, 99, or 100. In addition, each of `m` and `n` can independently
be 1, 2 or 3.
[0105] With regard to pyrazine derivatives of the fifth embodiment,
each of X.sup.1 and X.sup.2 can independently be --CO.sub.2R.sup.1,
--COR.sup.2, or --CONR.sup.7R.sup.9 in some embodiments. In other
embodiments, each of X.sup.1 and X.sup.2 can independently be
--CO.sub.2R.sup.1 or --CONR.sup.7R.sup.9.
[0106] Y.sup.1 and Y.sup.2 may independently be --NR.sup.48R.sup.49
or
##STR00009##
in some embodiments. For instance, in some embodiments, each of
Y.sup.1 and Y.sup.2 can be --NR.sup.48R.sup.49.
[0107] In some embodiments, Z.sup.1 may be --O, --NR.sup.56, --S.
--SO or --SO.sub.2. For instance, in some embodiments, Z.sup.1 may
be --O or --NR.sup.56.
[0108] In some embodiments, each of R.sup.1 to R.sup.7 may
independently be
--(CH.sub.2).sub.aNR.sup.10CONR.sup.11(CH.sub.2).sub.b(CH.sub.2CH.sub.-
2O).sub.cR.sup.20,
--(CH.sub.2).sub.aCONR.sup.14(CH.sub.2).sub.b(CH.sub.2CH.sub.2O).sub.cR.s-
up.22,
--(CH.sub.2).sub.aSO.sub.2NR.sup.15(CH.sub.2).sub.b(CH.sub.2CH.sub.-
2O)R.sup.23,
--(CH.sub.2).sub.aSO.sub.2NR.sup.16(CH.sub.2).sub.b(CH.sub.2CH.sub.2O).su-
b.cR.sup.24,
--(CH.sub.2).sub.aNR.sup.17CO(CH.sub.2).sub.b(CH.sub.2CH.sub.2O).sub.cR.s-
up.25,
--(CH.sub.2).sub.aNR.sup.18CO.sub.2(CH.sub.2).sub.b(CH.sub.2CH.sub.-
2O).sub.cR.sup.26, or
--(CH.sub.2).sub.aOC(O)NR.sup.19(CH.sub.2).sub.b(CH.sub.2CH.sub.2O).sub.c-
R.sup.27. For instance, in some embodiments, each of R.sup.1 to
R.sup.6 may be
--(CH.sub.2).sub.aNR.sup.10CONR.sup.11(CH.sub.2).sub.b(CH.sub.2CH.-
sub.2O).sub.cR.sup.20. In other embodiments, each of R.sup.1 to
R.sup.7 may independently be
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cNR.sup.12CSNR.-
sup.13(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.21,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cCONR.sup.14(CH-
.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.22,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cNR.sup.15SO.su-
b.2(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.23,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cSO.sub.2NR.sup-
.16(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.24,
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cNR.sup.18CO.su-
b.2(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.26, or
--(CH.sub.2).sub.a(CH.sub.2CH.sub.2O).sub.b(CH.sub.2).sub.cOC(O)NR.sup.19-
(CH.sub.2).sub.d(CH.sub.2CH.sub.2O).sub.eR.sup.27.
[0109] In some embodiments, each of R.sup.20 to R.sup.27 may
independently be --H, --CH.sub.3,
--(CH.sub.2).sub.fNR.sup.30CSNR.sup.31(CH.sub.2).sub.g(CH.sub.2CH.sub.2O)-
.sub.hR.sup.39,--(CH.sub.2).sub.fC(O)NR.sup.32(CH.sub.2).sub.g(CH.sub.2CH.-
sub.2O).sub.hR.sup.40,
--(CH.sub.2).sub.fS(O).sub.2NR.sup.33(CH.sub.2).sub.g(CH.sub.2CH.sub.2O).-
sub.hR.sup.41,
--(CH.sub.2).sub.fNR.sup.34S(O).sub.2(CH.sub.2).sub.g(CH.sub.2CH.sub.2O).-
sub.hR.sup.42,
--(CH.sub.2).sub.fNR.sup.36C(O)O(CH.sub.2).sub.g(CH.sub.2CH.sub.2O).sub.h-
R.sup.44,
--(CH.sub.2).sub.fOC(O)NR.sup.37(CH.sub.2).sub.g(CH.sub.2CH.sub.-
2O).sub.hR.sup.45, --CO(AA), or --CONH(PS).
[0110] In some embodiments, each of R.sup.38 to R.sup.45 may
independently be --H or --CH.sub.3.
[0111] In some embodiments, R.sup.46 to R.sup.57 may independently
be --H, --(CH.sub.2).sub.cOR.sup.68,
--CH.sub.2(CHOH).sub.cR.sup.69, --CH.sub.2(CHOH).sub.cCO.sub.2H,
--(CHCO.sub.2H).sub.cCO.sub.2H,
--(CH.sub.2).sub.cNR.sup.70R.sup.71,
--CH[(CH.sub.2).sub.fNH.sub.2].sub.cCO.sub.2H,
--CH[(CH.sub.2).sub.fNH.sub.2].sub.cCH.sub.2OH,
--CH.sub.2(CHNH.sub.2).sub.cCH.sub.2NR.sup.72R.sup.73,
--(CH.sub.2CH.sub.2O).sub.eR.sup.74,
--(CH.sub.2).sub.cCO(CH.sub.2CH.sub.2O).sub.eR.sup.75,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.58C(O)N-
R.sup.59(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.76,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.60C(S)N-
R.sup.61(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.77,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kC(O)NR.sup.62(-
CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.78,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kS(O).sub.2NR.s-
up.63(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.79,
--(CH.sub.2).sub.i( CH.sub.2
CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.64S(O).sub.2(CH.sub.2).sub.l(CH.su-
b.2CH.sub.2O).sub.oR.sup.80,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.65C(O)(-
CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.81,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kNR.sup.66C(O)O-
(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.82,
--(CH.sub.2).sub.i(CH.sub.2CH.sub.2O).sub.j(CH.sub.2).sub.kOC(O)NR.sup.67-
(CH.sub.2).sub.l(CH.sub.2CH.sub.2O).sub.oR.sup.83,
--(CH.sub.2).sub.aSO.sub.3H, --(CH.sub.2).sub.aSO.sub.3.sup.-,
--(CH.sub.2).sub.aOSO.sub.3H, --(CH.sub.2).sub.aOSO.sub.3.sup.-,
--(CH.sub.2).sub.aNHSO.sub.3H, or
--(CH.sub.2).sub.aNHSO.sub.3.sup.-.
[0112] As stated above, (AA) is polypeptide chain including one or
more natural or unnatural cc-amino acids linked together by peptide
bonds. The polypeptide chain (AA) may be a homopolypeptide chain or
a heteropolypeptide chain, and may be any appropriate length. For
instance, in some embodiments, the polypeptide chain may include 1,
2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,
21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,
38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54,
55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71,
72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88,
89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 or 100 .alpha.-amino
acid(s), 1 to 90 .alpha.-amino acid(s), 1 to 80 .alpha.-amino
acid(s), 1 to 70 .alpha.-amino acid(s), 1 to 60 .alpha.-amino
acid(s), 1 to 50 .alpha.-amino acid(s), 1 to 40 .alpha.-amino
acid(s), 1 to 30 .alpha.-amino acid(s), 1 to 20 .alpha.-amino
acid(s), or even 1 to 10 .alpha.-amino acid(s). In some
embodiments, the .alpha.-amino acids of the polypeptide chain (AA)
are selected from aspartic acid, asparigine, arginine, histidine,
lysine, glutamic acid, glutamine, serine, and homoserine. In some
embodiments, the .alpha.-amino acids of the polypeptide chain (AA)
are selected from aspartic acid, glutamic acid, serine, and
homoserine. In some embodiments, the polypeptide chain (AA) refers
to a single amino (e.g., either aspartic acid or serine).
[0113] As stated above, (PS) is a sulfated or non-sulfated
polysaccharide chain including one or more monosaccharide units
connected by glycosidic linkages. The polysaccharide chain (PS) may
be any appropriate length. For instance, in some embodiments, the
polysaccharide chain may include 1, 2, 3, 4, 5, 6, 7, 3, 9, 10, 11,
12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28,
29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42,43, 44, 45,
46,47, 48,49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62,
63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96,
97, 98, 99 or 100 monosaccharide unit(s), 1 to 90 monosaccharide
unit(s), 1 to 80 monosaccharide unit(s), 1 to 70 monosaccharide
unit(s), 1 to 60 monosaccharide unit(s), 1 to 50 monosaccharide
unit(s), 1 to 40 monosaccharide unit(s), 1 to 30 monosaccharide
unit(s), 1 to 20 monosaccharide unit(s), or even 1 to 10
monosaccharide unit(s). In some embodiments, the polysaccharide
chain (PS) is a homopolysaccharide chain consisting of either
pentose or hexose monosaccharide units. In other embodiments, the
polysaccharide chain (PS) is a heteropolysaccharide chain
consisting of one or both pentose and hexose monosaccharide units.
In some embodiments, the monosaccharide units of the polysaccharide
chain (PS) are selected from the group consisting of glucose,
fructose, mannose, xylose and ribose. In some embodiments, the
polysaccharide chain (PS) refers to a single monosaccharide unit
(e.g., either glucose or fructose).
[0114] Still referring to pyrazine derivatives of Formulas I and II
in some embodiments, each of `a`, `d`, `g`, `i`, `l`, and `q` may
independently be 1, 2, 3, 4, 5 or 6. Each of `e`, `h`, `o`, and `s`
may independentlybe 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19 or 20 in some embodiments. Similarly, in some
embodiments, each of `b` and `j` may independently be 0, 1, 2, 3,
4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20. In
some embodiments, each of `m` and `n` may independently be 1 or
2.
[0115] Any of the pyrazine derivatives described above may exhibit
any appropriate molecular weight. For instance, in some
embodiments, a pyrazine derivative of the invention may have a
molecular weight of no more than about 20000. In other embodiments,
a pyrazine derivative of the invention may have a molecular weight
of no more than about 15000, 14000, 13000, 12000, 11000, 10000,
9000, 8000, 7000, 6000, 5000, 4500, 4000, 3500, 3000, 2500, 2000,
1500, 1000, 900, 800, 700, 600, 500, 400, 300, 200, or even 100.
Other embodiments may have molecular weights that are greater than
about 20000.
[0116] Yet another aspect of the invention is directed to methods
of using pyrazine derivatives described herein. In such methods, a
pyrazine derivative is administered to a patient and utilized in a
medical photodiagnostic and/or imaging procedure (e.g., assessing
renal function).
[0117] In accordance with one protocol for assessing physiological
function of body cells, an effective amount of a pyrazine
derivative described herein is administered into a body of a
patient. An appropriate dosage of the pyrazine derivate that is
administered to the patient is readily determinable by one of
ordinary skill in the art and may vary according to the clinical
procedure contemplated (e.g., ranging from about 1 nanomolar to
about 100 micromolar). The administration of the pyrazine
derivative to the patient may occur in any of a number of
appropriate fashions including, but not limited to: (L)
intravenous, intraperitoneal, or subcutaneous injection or
infusion; (2) oral administration; (3) transdermal absorption
through the skin; and (4) inhalation.
[0118] Pyrazine derivatives of this invention may be administered
as solutions in most pharmaceutically acceptable intravenous
vehicles known in the art. Pharmaceutically acceptable vehicles
that are well known to those skilled in the art include, but are
not limited to, 0.01-0.1 M phosphate buffer or 0.8% saline.
Additionally, pharmaceutically acceptable carriers may be aqueous
or non-aqueous solutions, suspensions, emulsions, or appropriate
combinations thereof. Examples of non-aqueous solvents are
propylene glycol, polyethylene glycol, vegetable oils such as olive
oil, and injectable organic esters such as ethyl oleate. Examples
of aqueous carriers are water, alcoholic/aqueous solutions,
emulsions or suspensions, including saline and buffered media.
Exemplary parenteral vehicles include sodium chloride solution,
Ringer's dextrose, dextrose and sodium chloride, lactated Ringer's
or fixed oils. Exemplary intravenous vehicles include fluid and
nutrient replenishers, electrolyte replenishers such as those based
on Ringer's dextrose, and the like. Preservatives and other
additives may be present, such as, for example, antimicrobials, and
antioxidants, collating agents, inert gases and the like.
[0119] Suitable diluents, preservatives, solubilizers, emulsifiers,
adjuvant and/or carriers are also suitable excipients. Such
compositions tend to be liquids or lyophilized or otherwise dried
formulations and include diluents of various buffer content (e.g.,
Tris-HCl, acetate, phosphate), pH and ionic strength, additives
such as albumin or gelatin to prevent absorption to surfaces,
detergents (e.g., Tween 20, Tween 80, Pluronic F68, bile acid
salts), solubilizing agents (e.g., glycerol, polyethylene
glycerol), anti-oxidants (e.g., ascorbic acid, sodium
metabisulfite), preservatives (e.g., Thimerosal, benzyl alcohol,
parabens), bulking substances or tonicity modifiers (e.g., lactose,
mannitol), complexation with metal ions, or incorporation of the
material into or onto particulate preparations of polymeric
compounds such as polylactic acid, polglycolic acid, hydrogels,
etc, or onto liposomes, microemulsions, micelles, unilamellar or
multilamellar vesicles, erythrocyte ghosts, or spheroplasts. Such
compositions may likely influence the physical state, solubility,
stability, rate of in vivo release, and/or rate of in vivo
clearance.
[0120] Still referring to the above-mentioned method of use, the
pyrazine derivative is exposed to visible and/or near infrared
light. This exposure of the pyrazine derivate to light may occur at
any appropriate time but preferably occurs while the pyrazine
derivative is located in the body. Due to this exposure of the
pyrazine derivate to the visible and/or infrared light, the
pyrazine derivate emanates spectral energy (e.g., visible and/or
near infrared light) that may be detected by appropriate detection
equipment. The spectral energy emanated from the pyrazine
derivative may tend to be a wavelength range greater than a
wavelength range of the light to which the pyrazine derivative was
exposed. For example, if a given pyrazine derivative absorbs light
of about 700 nm, the pyrazine derivative may emit light of about
745 nm.
[0121] Detection of a pyrazine derivate (or more particularly, the
light emanating therefrom) may be achieved through optical
fluorescence, absorbance, and/or light scattering procedures known
in the art. In one embodiment, this detection of emanated spectral
energy may be characterized as a collection of the emanated
spectral energy and a generation of electrical signal indicative of
the collected spectral energy. The mechanism(s) utilized to detect
the spectral energy from a given pyrazine derivative that is
present in the body may be designed to detect only selected
wavelengths (or wavelength ranges) and/or may include one or more
appropriate spectral filters. Various catheters, endoscopes, ear
clips, hand bands, head bands, surface coils, finger probes and the
like may be utilized to expose the pyrazine derivative to light
and/or to detect light emanating therefrom.[22] This detection of
spectral energy may be accomplished at one or more times
intermittently or may be substantially continuous.
[0122] Renal function of the patient may be determined based on the
detected spectral energy. This may be achieved by using data
indicative of the detected spectral energy and generating an
intensity/time profile indicative of a clearance of the pyrazine
derivative from the body. This profile may be correlated to a
physiological or pathological condition. For example, the patient's
clearance profiles and/or clearance rates may be compared to known
clearance profiles and/or rates to assess the patient's renal
function and to diagnose the patient's physiological condition. In
the case of analyzing the presence of the pyrazine derivative in
bodily fluids, concentration/time curves may be generated and
analyzed (preferably in real time) using an appropriate
microprocessor to diagnose renal function.
[0123] Physiological function may be assessed by: (1) comparing
differences in manners in which normal and impaired cells remove a
pyrazine derivative of the invention from the bloodstream; (2)
measuring a rate or an accumulation of a pyrazine derivative of the
invention in the organs or tissues; and/or (3) obtaining
tomographic images of organs or tissues having a pyrazine
derivative of the invention associated therewith. For example,
blood pool clearance may be measured non-invasively from convenient
surface capillaries such as those found in an ear lobe or a finger
or may be measured invasively using an appropriate instrument such
as an endovascular catheter. Accumulation of a pyrazine derivative
of the invention within cells of interest may be assessed in a
similar fashion.
[0124] A modified pulmonary artery catheter may also be utilized
to, inter alia, make the desired measurements of spectral energy
emanating from a pyrazine derivative of the invention.[23] The
ability for a pulmonary catheter to detect spectral energy
emanating from a pyrazine derivative of the invention is a distinct
improvement over current pulmonary artery catheters that measure
only intravascular pressures, cardiac output and other derived
measures of blood flow. Traditionally, critically ill patients have
been managed using only the above-listed parameters, and their
treatment has tended to be dependent upon intermittent blood
sampling and testing for assessment of renal function. These
traditional parameters provide for discontinuous data and are
frequently misleading in many patient populations.
[0125] Modification of a standard pulmonary artery catheter only
requires making a fiber optic sensor thereof wavelength-specific.
Catheters that incorporate fiber optic technology for measuring
mixed venous oxygen saturation exist currently. In one
characterization, it may be said that the modified pulmonary artery
catheter incorporates a wavelength-specific optical sensor into a
tip of a standard pulmonary artery catheter. This
wavelength-specific optical sensor may be utilized to monitor renal
function-specific elimination of a designed optically detectable
chemical entity such as the pyrazine derivatives of the present
invention. Thus, by a method analogous to a dye dilution curve,
real-time renal function may be monitored by the
disappearance/clearance of an optically detected compound.
[0126] Yet another aspect of the invention is directed to
pharmaceutically acceptable compositions, each of which includes
one or more pyrazine derivatives disclosed herein. The phrase
"pharmaceutically acceptable" herein refers substances that are,
within the scope of sound medical judgment, suitable for use in
contact with relevant tissues of humans and animals without undue
toxicity, irritation, allergic response and the like, and are
commensurate with a reasonable benefit/risk ratio These
compositions of the invention may include one or more appropriate
excipients such as, but not limited to, suitable diluents,
preservatives, solubilizers, emulsifiers, adjuvant and/or carriers.
One example of a composition of the invention may include at least
one pyrazine derivative of Formula I and/or at least one pyrazine
derivative of Formula II.
[0127] Yet another aspect of the invention is directed to methods
of determining renal function using pyrazine derivatives such as
those described above (e.g., with regard to Formulas I and II). In
these methods, an effective amount of a pyrazine derivative is
administered into the body of a patient (e.g., a mammal such as a
human or animal subject). Incidentally, an "effective amount"
herein generally refers to an amount of pyrazine derivative that is
sufficient to enable renal clearance to be analyzed. The pyrazine
derivative in the body of the patient is exposed to at least one of
visible and near infrared light. Due to this exposure of the
pyrazine derivative to the visible and/or infrared light, the
pyrazine derivative emanates spectral energy that may be detected
by appropriate detection equipment. This spectral energy emanating
from the pyrazine derivative may be detected using an appropriate
detection mechanism such as an invasive or non-invasive optical
probe. Herein, "emanating" or the like refers to spectral energy
that is emitted and/or fluoresced from a pyrazine derivative. Renal
function may be determined based the spectral energy that is
detected. For example, an initial amount of the amount of pyrazine
derivative present in the body of a patient may be determined by a
magnitude/intensity of light emanated from the pyrazine derivative
that is detected (e.g., in the bloodstream). As the pyrazine
derivative is cleared from the body, the magnitude/intensity of
detected light generally diminishes. Accordingly, a rate at which
this magnitude of detected light diminishes may be correlated to a
renal clearance rate of the patient. This detection may be done
periodically or in substantially real time (providing a
substantially continuous monitoring of renal function). Indeed,
methods of the present invention enable renal function/clearance to
be determined via detecting one or both a change and a rate of
change of the detected magnitude of spectral energy (indicative of
an amount of the pyrazine derivative that has not been cleared)
from the portion of the pyrazine derivative that remains in the
body.
[0128] Yet another aspect of the invention is directed to a process
for producing pyrazine derivatives. In this process, an
aminopyrazine compound and a carbonyl compound are combined in the
presence of a reducing agent. For example, in some embodiments, a
diaminopyrazine and a carbonyl compound can be combined in the
presence of a reducing agent to produce an N,N'-alkylated
diaminopyrazine.
[0129] In some embodiments, the aminopyrazine compound, the
carbonyl compound, and a solvent may be combined in the presence of
the reducing agent. The various components that are combined may be
at any appropriate temperature during the process (e.g., during the
combining). Moreover, the process or a portion thereof (e.g., the
actual combining of the various components) may take place in an
environment of any appropriate temperature. For instance, the
temperature of one or more of the various components and/or the
environment may be within a range of -20.degree. to 50.degree. C.
(inclusive) during the combining in some embodiments. In other
words, the temperature can be -20, -19, -18, -17, -16, -15, -14,
-13, -12, -11, -10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3,
4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50 degrees Celsius.
In other embodiments, the temperature of one or more of the various
components and/or the environment may be within a range of
-5.degree. to 30.degree. C. (inclusive) during the combining. In
other words, the temperature can be -5, -4, -3, -2, -1, 0, 1, 2, 3,
4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
22, 23, 24, 25, 26, 27, 283 29, or 30 degrees Celsius.
[0130] The carbonyl compound used in the process may be any
appropriate carbonyl compound. For instance, in some embodiments,
the carbonyl compound may be of Formula III below.
##STR00010##
[0131] In Formula III, each of R.sup.1 and R.sup.2 is independently
hydrogen, C.sub.1-C.sub.10 alkyl, C.sub.5-C.sub.20 aralkyl,
C.sub.1-C.sub.20 hydroxyalkyl, C.sub.2-C.sub.20 polyhydroxyalkyl,
--(CH.sub.2).sub.nCO.sub.2R.sup.3,
--(CH.sub.2CH.sub.2O).sub.mR.sup.4 or mono- or poly-saccharide
containing 1 to 50 units.
[0132] Referring to R.sup.1 and R.sup.2 of Formula III, m and n may
be any appropriate integers. For instance, in some embodiments,
each of m and n is independently 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28,
29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45,
46, 47, 48, 49 or 50. In some embodiments, each of m and n may
independently be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30. In
other embodiments, m and n may independently be 1, 2, 3, 4, 5, 6,
7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20. In yet other
embodiments, m and n may independently be 1, 2, 3, 4, 5, 6, 7, 8, 9
or 10.
[0133] Still referring to R.sup.1 and R.sup.2 of Formula III, each
occurrence of R.sup.3 and R.sup.4 is independently hydrogen,
C.sub.1-C.sub.10 alkyl, C.sub.5-C.sub.20 aralkyl, C.sub.1-C.sub.10
acyl, C.sub.1-C.sub.20 hydroxyalkyl, C.sub.2-C.sub.20
polyhydroxyalkyl, or mono- or poly-saccharide containing 1 to 50
units. For instance, in some embodiments, each of R.sup.3 and
R.sup.4 is independently hydrogen, C.sub.1-C.sub.10 alkyl,
C.sub.1-C.sub.20 hydroxyalkyl, or C.sub.2-C.sub.20
polyhydroxyalkyl.
[0134] The aminopyrazine compound utilized in the process may be
any appropriate aminopyrazine compound. For instance, the
aminopyrazine compound utilized may be a compound of the following
Formula IV or V below.
##STR00011##
[0135] With regard to Formulas IV and V above, each X and Y is
independently hydrogen, C.sub.1-C.sub.10 alkyl, --OR.sup.5,
--SR.sup.6, --NR.sup.7R.sup.8, --N(R.sup.9)COR.sup.10, halo,
trihaloakyl, --CN, --NO.sub.2, --CO-Z-R.sup.11, --SOR.sup.12,
--SO.sub.2R.sup.13, --SO.sub.2OR.sup.14, or
--PO.sub.3R.sup.15R.sup.16. Z is a single bond, --O--,
--NR.sup.17--, --NH(CH.sub.2).sub.pNH--, --NH(CH.sub.2).sub.pO--,
--NH(CH.sub.2).sub.pCO--, --NH(CH.sub.2).sub.pNHCO--,
--NH(CH.sub.2).sub.pCONH--, --NH(CH.sub.2).sub.pNHCONH--,
--NH(CH.sub.2).sub.pNHCSNH--, or --NH(CH.sub.2).sub.pNHCO.sub.2--.
Each of R.sup.5 to R.sup.17 is independently hydrogen,
C.sub.1-C.sub.10 alkyl, C.sub.5-C.sub.20 aralkyl, C.sub.1-C.sub.10
acyl, C.sub.1-C.sub.20 hydroxyalkyl, C.sub.2-C.sub.20
polyhydroxyalkyl, --(CH.sub.2CH.sub.2O).sub.qR.sup.18, or mono- or
poly-saccharide containing 1 to 50 units. R.sup.18 is hydrogen,
C.sub.1-C.sub.10 alkyl, C.sub.5-C.sub.20 aralkyl, C.sub.1-C.sub.10
acyl, C.sub.1-C.sub.20 hydroxyalkyl, C.sub.2-C.sub.20
polyhydroxyalkyl, or mono- or poly-saccharide containing 1 to 50
units. The integer p 0, 1, 2, 3, 4, 5 or 6. Further, the integer q
is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50.
[0136] In some compounds of Formulas IV and V above, each of X and
Y may be --CN in some embodiments and --CO-Z-R.sup.11 in other
embodiments. In embodiments of compounds of Formulas IV and V that
include R.sup.11, R.sup.11 of some embodiments may be hydrogen,
C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.20 hydroxyalkyl, or
C.sub.2-C.sub.20 polyhydroxyalkyl. When each of X and Y is
--CO-Z-R.sup.11, Z may be --NR.sup.17-- in some embodiments,
--NH(CH.sub.12).sub.pNH-- in other embodiments, and
--NH(CH.sub.2).sub.pCO-- in other embodiments. In the case that Z
is --NR.sup.17--, R.sup.17 of some embodiments may be hydrogen or
C.sub.1-C.sub.10 alkyl. In the case that Z is either
NH(CH.sub.2).sub.pNH-- or --NH(CH.sub.2).sub.pCO--, the integer p
of some embodiments may be 0, 1, 2, 3 or 4.
[0137] The reducing agent utilized in the process may be any
appropriate reducing agent. For instance, in some embodiments, the
reducing agent is ammonium formate, diimide, Zn/HCl, sodium
triacetoxyborohydride, sodium borohydride, pyridine/borane, lithium
aluminium hydride, lithium borohydride, sodium cyanoborohydride,
sodium amalgam, H.sub.2/Pd/C, H.sub.2/Pt/C, H.sub.2/R/C,
H.sub.2/Raney.RTM. Nickel, or any combination thereof. In some
embodiments, the reducing agent includes or is sodium
triacetoxyborohydride. In some embodiments, the reducing agent
includes or is sodium cyanoborohydride.
[0138] In the case that a solvent is utilized in the process, the
solvent may be any appropriate solvent such as, for example, water,
C.sub.1-C.sub.8 alcohol, C.sub.1-C.sub.8 ether, C.sub.1-C.sub.8
ester, dimethyl formamide, dimethyl acetamide, acetic acid,
trifluoroacetic acid, dimethyl sulfoxide, or any combination
thereof. In some embodiments, the solvent may be methanol, ethanol,
isopropyl alcohol, tetrahydrofuran, dioxane, glyme, dimethyl
formamide, dimethyl sulfoxide, or any combination thereof.
[0139] The order of addition of reagents in the process may vary
(e.g., depending on the nature of the starting materials used). For
example, the present process contemplates the addition of the
reducing agent to the mixture of the aminopyrazine and the carbonyl
compound, and likewise it contemplates the addition of the carbonyl
compound to a mixture of the aminopyrazine and the reducing agent,
as well as the addition of the aminopyrazine to a mixture of the
carbonyl compound and the reducing agent provided that the reducing
agent does not substantially decompose the carbonyl compound. In
short, any suitable order of addition may be utilized.
[0140] Compound 18 below is an N,N'-alkylated diaminopyrazine that
was produced using a process described herein and that could be
used to assess renal function.
##STR00012##
[0141] Pyrazine derivatives made using a process described herein
may be utilized in a number of appropriate methods and procedures
(e.g., medical procedures). For instance, pyrazine derivatives made
using a process described herein may be utilized in assessing renal
function of a medical patient and/or as intermediates in processes
for manufacturing pyrazine derivatives and/or compositions that
include pyrazine derivatives (e.g., for use in assessing renal
function of medical patients).
EXAMPLES
[0142] Unless otherwise noted, all reagents were used as supplied.
Organic extracts were dried over anhydrous Na.sub.2SO.sub.4 and
filtered using a fluted filter paper (P8). Solvents were removed on
a rotary evaporator under reduced pressure. RP-LC/MS (ESI, positive
ion mode) analyses were carried out on a Waters Micromass ZQ system
equipped with a PDA detector using either a BDS Hypersil C18 3
.mu.m (50 mm.times.4.6 mm) or a ThermoElectron Hypersil Gold C18 3
.mu.m (4.6 mm.times.50 mm) column. Compounds were injected using a
gradient condition (5 to 50-95% B/6 min) with a flow rate of 1
mL/min (mobile phase A: 0.05% TFA in H.sub.2O; mobile phase B:
0.05% TFA in CH.sub.3CN). Chemical shifts are expressed in parts
per million (.delta.) relative to TMS (.delta.=0) as an internal
standard and coupling constants (J) are reported in Hz.
Example 1
Protocol for Assessing Renal Function
[0143] An example of an in vivo renal monitoring assembly 10 is
shown in FIG. 1 and includes a light source 12 and a data
processing system 14. The light source 12 generally includes or is
interconnected with an appropriate device for exposing at least a
portion of a patient's body to light therefrom. Examples of
appropriate devices that may be interconnected with or be a part of
the light source 12 include, but are not limited to, catheters,
endoscopes, fiber optics, ear clips, hand bands, head bands,
forehead sensors, surface coils, and finger probes. Indeed, any of
a number of devices capable of emitting visible and/or near
infrared light of the light source may be employed in the renal
monitoring assembly 10.
[0144] Still referring to FIG. 1, the data processing system 14 of
the renal monitoring assembly 10 may be any appropriate system
capable of detecting spectral energy and processing data indicative
of the spectral energy. For instance, the data processing system 14
may include one or more lenses (e.g., to direct and/or focus
spectral energy), one or more filters (e.g., to filter out
undesired wavelengths of spectral energy), a photodiode (e.g., to
collect the spectral energy and convert the same into electrical
signal indicative of the detected spectral energy), an amplifier
(e.g., to amplify electrical signal from the photodiode), and a
processing unit (e.g., to process the electrical signal from the
photodiode). This data processing system 14 is configured to
manipulate collected spectral data and generate an intensity/time
profile and/or a concentration/time curve indicative of renal
clearance of a pyrazine derivative of the present invention from
the patient 20. Indeed, the data processing system 14 may be
configured to generate appropriate renal function data by comparing
differences in manners in which normal and impaired cells remove
the pyrazine derivative from the bloodstream, to determine a rate
or an accumulation of the pyrazine derivative in organs or tissues
of the patient 20, and/or to provide tomographic images of organs
or tissues having the pyrazine derivative associated therewith.
[0145] FIG. 2 provides a clearance curve in Sprague-Dawley rats for
compound 18 of the present invention, the compound being described
in greater detail below. Four Sprague-Dawley rats were used to
obtain the experimental results depicted in FIG. 2, with each of
the four lines of the graph representing data obtained from an
individual rat. The rats were injected intravenously with 1 ml of a
2 mmol solution of compound 18 in phosphate-buffered saline (PBS),
giving a final concentration of compound 18 in each animal of
approximately 6 .mu.mol/kg. The presence of compound 18 in each of
the animals was monitored over time and measured in Relative
Fluorescence Units (RFUs). The clearance curve in FIG. 2 provides
RFUs over time for each of the four rats. As shown in FIG. 2,
clearance of compound 18 began rapidly in each of the animals, and
proceeded at a rapid pace from about 250 minutes to about 750
minutes. The clearance rate then began to level, with complete
clearance of compound 18 occurring at approximately 6000
minutes.
[0146] FIG. 3 provides a bar graph comparison of the clearance
rates of an iothalamate reference standard and compound 18.
Spraque-Dawley rats were again used as animal models for studying
the clearance rates. Iothalamate clearance rates were measured in
five rats, whereas clearance rates for compound 18 were measured in
six rats. The clearance rates are expressed in FIG. 3 in terms of
milliliters per minute. As can be seen from the figure, the
clearance rate of iothalamate and compound 18 were observed to be
virtually the same. Thus, compound 18 provides clearance rates
comparable to the accepted standard of iothalamate, but without the
necessity for radiologic or other harmful imaging methods that are
commonly used with iothalamate.
[0147] In one protocol for determining renal function, an effective
amount of a pyrazine derivative of the invention is administered to
the patient (e-g., in the form for a pharmaceutically acceptable
composition). At least a portion of the body of the patient 20 is
exposed to visible and/or near infrared light from the light source
12 as indicated by arrow 16. For instance, the light from the light
source 12 may be delivered via a fiber optic that is affixed to an
ear of the patient 20. The patient may be exposed to the light from
the light source 12 before or after administration of the pyrazine
derivative to the patient 20. In some cases, it may be beneficial
to generate a background or baseline reading of light being emitted
from the body of the patient 20 (due to exposure to the light from
the light source 12) before administering the pyrazine derivative
to the patient 20. When the pyrazine derivative that is in the body
of the patient 20 is exposed to the light from the light source 12,
the pyrazine derivative emanates light (indicated by arrow 18) that
is detected/collected by the data processing system 14. Initially,
administration of the pyrazine derivative to the patient 20
generally enables an initial spectral signal indicative of the
initial content of the pyrazine derivative in the patient 20. The
spectral signal then tends to decay as a function of time as the
pyrazine derivative is cleared from the patient 20. This decay in
the spectral signal as a function of time is indicative of the
patient's renal function. For example, in a first patient
exhibiting healthy/normal renal function, the spectral signal may
decay back to a baseline in a time of T. However, a spectral signal
indicative of a second patient exhibiting deficient renal function
may decay back to a baseline in a time of T+4 hours. As such, the
patient 20 may be exposed to the light from the light source 12 for
any amount of time appropriate for providing the desired renal
function data. Likewise, the data processing system 14 may be
allowed to collect/detect spectral energy for any amount of time
appropriate for providing the desired renal function data.
Example 2
Synthesis of Representative Pyrazine PEG Analogues
[0148] Unless otherwise noted, all reagents in this Example were
used as supplied. Organic extracts were dried over anhydrous
Na.sub.2SO.sub.4 and filtered using a fluted filter paper (P8).
Solvents were removed on a rotary evaporator under reduced
pressure. RP-LC/MS (ESI, positive ion mode) analyses were carried
out on a Waters Micromass ZQ system equipped with a PDA detector
using either a BDS Hypersil C18 3 .mu.m (50 mm.times.4.6 mm) or a
ThermoElectron Hypersil Gold C18 3 .mu.m (4.6 mm.times.50 mm)
column. Compounds were injected using a gradient condition (5 to
50-95% B/6 min) with a flow rate of 1 mL/min (mobile phase A: 0.05%
TFA in H.sub.2O; mobile phase B: 0.05% TFA in CH.sub.3CN). Chemical
shifts are expressed in parts per million (.delta.) relative to TMS
(.delta.=0) as an internal standard and coupling constants (J) are
reported in Hz.
A. Diethyl 3,6-bis(benzylamino)pyrazine-2,5-dicarboxylate (7)
##STR00013##
[0150] To a well-stirred red suspension of diethyl
3,6-diaminopyrazine-2,5-dicarboxylate (0.127 g, 0.500 mmol).sup.2
in anhyd 1,2-dichloroethane (DCE, 20 mL), benzaldehyde (0.202 mL,
2.00 mmol) was added, and the reaction flask was immersed in an ice
bath. Then HOAc (0.115 mL, 2.00 mmol) was added followed by the
addition of sodium triacetoxyborohydride (0.424 g, 2.00 mmol) in
small portions over a 15 min period. The resulting suspension was
slowly allowed to warm to r.t. and stirred overnight (ca. 16 h;
RP-LC/MS analysis indicated the presence of some substrate) in an
atmosphere of argon. At this stage, the reaction mixture was
treated with more benzaldehyde (0.202 mL, 2.00 mmol), HOAc (0.115
mL, 2.00 mmol), and sodium triacetoxyborohydride (0.424 g, 2.00
mmol) as described above, and the reaction was continued overnight
(ca. 24 h; RP-LC/MS analysis indicated a complete reaction). The
reaction was quenched by a slow addition of satd NaHCO.sub.3 (20
mL) while stirring at 0.degree. C. The biphasic mixture was stirred
for 30 min and extracted with CHCl.sub.3 (3.times.25 mL). The
combined organic extracts were successively washed with satd
NaHCO.sub.3, H.sub.2O, and brine (30 mL each). Removal of the
solvent gave 0.200 g of a red solid, which upon flash
chromatography over silica gel (CHCl.sub.3) afforded Example 1
(0.174 g, 80%) as a dark red powder: R.sub.f 0.49; .sup.1H NMR
(DMSO-d.sub.6) 7.60 (t, 2, J=5.9), 7.42 (dd, 4, J=7.7, 1.7),
7.28-7.18 (m, 6), 4.51 (d, 4, 5.9), 4.32 (q, 4, J=7.1), 1.30 (t, 6,
J=7.1); .sup.13C NMR (DMSO-d.sub.6) 165.36, 146.28, 140.07, 128.08,
128.03, 126.65, 124.80, 61.35, 44.39, 44.29, 14.13; RP-LC/MS (ESI)
m/z 435.3 (M+H).sup.+, 457.2 (M+Na).sup.+ (t.sub.R=5.53 min, 5-95%
B). Anal. Calcd for C.sub.24H.sub.26N.sub.4O.sub.4: C, 66.34; H,
6.03; N, 12.89. Found: C, 66.10; H, 5.98; N, 12.67.
B.
3,6-Bis(propylamino)-N.sup.2,N.sup.5-bis[2-(tert-butoxycarbonyl)aminoet-
hyl]pyrazine-2,5-dicarboxamide (8)
##STR00014##
[0152] To a partially-dissolved yellow suspension of
3,6-Diamino-N.sup.2,N.sup.5-bis[2-(tert-butoxycarbonyl)aminoethyl]pyrazin-
e-2,5-dicarboxamide (0.483 g, 1.00 mmol).sup.8 in anhydrous DCE (20
mL), propionaldehyde (0.290 mL, 4.02 mmol) and HOAc (0.290 mL, 5.03
mmol) were added with stirring at 0.degree. C. under argon
atmosphere. The resulting somewhat lighter suspension was allowed
to stir for 5 min before the addition of sodium
triacetoxyborohydride (0.848 g, 4.00 mmol) in small portions over a
10 min period. The reddish suspension was slowly allowed to warm to
r.t. and stirred overnight (ca. 19 h) in an atmosphere of argon.
The reaction was quenched by a slow addition of satd NaHCO.sub.3
(20 mL) at 0.degree. C. The biphasic mixture was stirred for 30 min
and extracted with CHCl.sub.3 (3.times.25 mL). The combined organic
extracts were successively washed with H.sub.2O and brine (50 mL
each). Removal of the solvent gave 0.680 g of a red solid, which
upon flash chromatography over silica gel [CH.sub.2Cl.sub.2-EtOAc
(17:3 to 3:1, v/v)] afforded Example 2 (0.454 g, 80%) as acrimson
red solid: R.sub.f 0.44 [CH.sub.2Cl.sub.2-EtOAc (7:3, v/v)];
.sup.1H NMR (CDCl.sub.3) 8.13 (br s, 2), 7.78 (t, 2, J=5.4), 4.87
(br s, 2), 3.53 (q, 4, J=5.9), 3.39-3.34 (quintet, 8), 1.70-1.63
(sextet, 4), 1.42 (s, 18), 1.01 (t, 6, J=7.4); .sup.13C NMR
(CDCl.sub.3) 166.84, 156.30, 146.01, 126.07, 79.55, 42.89, 40.44,
39.79, 28.32, 22.75, 11.82; RP-LC/MS (ESI) m/z 567.4 (M+H).sup.+,
589.4 (M+Na).sup.+ (t.sub.R=5.17 min, 5-95% B). Anal. Caled for
C.sub.26H.sub.46N.sub.8O.sub.6: C, 55.11; H, 8.18; N, 19.77. Found:
C, 55.17; H, 8.31; N, 19.53.
C. 3,6-Bis(benzylamino)-N.sup.2,N.sup.5-bis[2-(tert
butoxycarbonyl)aminoethyl]pyrazine-2,5-dicarboxamide (9)
##STR00015##
[0154] The reaction of
3,6-Diamino-N.sup.2,N.sup.5-bis[2-(tert-butoxycarbonyl)aminoethyl]pyrazin-
e-2,5-dicarboxamide (0.121 g, 0.250 mmol).sup.8 with benzaldehyde
(0.101 mL, 1.00 mmol) in the presence of HOAc (0.058 mL, 1.00 mmol)
and sodium triacetoxyborohydride (0.212 g, 1.00 mmol) in DCE (10
mL) was carried out overnight (ca. 16 h) as described in the
preparation of Example 2. After the usual work up, the brick-red
crude product (0.240 g) was subjected to flash chromatography over
silica gel [CHCl.sub.3-EtOAc (4:1, v/v)], and the residue
triturated with anhyd Et.sub.2O to give Example 3 (0.119 g, 72%) as
an orange powder: R.sub.f 0.40 [CHCl3-EtOAc (7:3, v/v)]; .sup.1H
NMR (CDCl.sub.3) 8.20 (br t, 2, J=5.0), 7.76 (br t, 2), 7.37-7.30
(m, 8), 7.25-7.21 (m, 2), 4.77 (br s, 2), 4.58 (d, 4, J=5.4),
3.44-3.40 (br q, 4), 3.31-3.25 (br q, 4), 1.43 (s, 18); RP-LC/MS
(ESI) m/z 663.2 (M+H).sup.+, 685.2 (N+Na).sup.+ (t.sub.R=4.30 min,
50-95% B). Anal. Calcd for C.sub.34H.sub.46N.sub.8O.sub.6: C,
61.61; H, 7.00; N, 16.91. Found: C, 61.72; H, 7.07; N, 16.89.
D.
3,6-Bis(4-methoxybenzylamino)-N.sup.2,N.sup.5-bis[2-(tert-butoxycarbony-
l)aminoethyl]pyrazine-2,5-dicarboxamide (10)
##STR00016##
[0156] The reaction of
3,6-Diamino-N.sup.2,N.sup.5-bis[2-(tert-butoxycarbonyl)aminoethyl]pyrazin-
e-2,5-dicarboxamide (0.483 g, 1.00 mmol).sup.8 with
4-methoxybenzaldehyde (0.485 mL, 4.00 mmol) in the presence of HOAc
(0.230 mL, 4.00 mmol) and sodium triacetoxyborohydride (0.848 g,
4.00 mmol) in DCE (25 mL) was carried out overnight as described in
the preparation of Example 2. After the usual work up, the
brick-red crude product (1.14 g) was subjected to flash
chromatography over silica gel [CHCl.sub.3-EtOAc (3:1, v/v)], and
the material obtained was recrystallized from EtOAc-Et.sub.2O to
give Example 4 (0.615 g, 85%) as an orange-red microcrystalline
solid: R.sub.f 0.30 [CHCl.sub.3-EtOAc (7:3, v/v)]; .sup.1H NMR
(CDCl.sub.3) 8.14 (br t, 2, J=5.0), 7.90 (br t, 2), 7.28 (d, 4,
J=8.5), 6.86 (d, 4, J=8.5), 4.82 (br t, 2), 4.52 (d, 4, J=5.4),
3.78 (s, 6), 3.46-3.43 (br q, 4), 3.33-3.28 (br q, 4), 1.42 (s,
18); RP-LC/MS (ESI) m/z 723.3 (M +H).sup.+, 745.3 (M+Na).sup.+
(t.sub.R=4.08 min, 50-95% B). Anal. Calcd for
C.sub.36H.sub.50N.sub.8O.sub.8: C, 59.82; H, 6.97; N, 15.50. Found:
C, 60.01; H, 7.05; N, 15.43.
E.
3,6-Bis(4-nitrobenzylamino)-N.sup.2,N.sup.5-bis[2-(tert-butoxycarbonyl)-
aminoethyl]pyrazine-2,5-dicarboxamide (11)
##STR00017##
[0158] The reaction of
3,6-Diamino-N.sup.2,N.sup.5-bis[2-(tert-butoxycarbonyl)aminoethyl]pyrazin-
e-2,5-dicarboxamide (0.121 g, 0.250 mmol).sup.8 with
4-nitrobenzaldehyde (0.151 mL, 1.00 mmol) in the presence of HOAc
(0.058 mL, 1.00 mmol) and sodium triacetoxyborohydride (0.212 g,
1.00 mmol) in DCE (10 mL) was carried out overnight (ca. 18 h) as
described in the preparation of Example 2. After the usual work up,
the brick-red crude product (0.260 g) was subjected to flash
chromatography over silica gel [CHCl.sub.3-EtOAc (7:3, v/v)], and
the residue recrystallized from EtOAc-Et.sub.2O to give Example 5
(0.155 g, 82%) as an orange microcrystalline solid: R.sub.f 0.33
[CHCl.sub.3-EtOAc (1:1, v/v)]; .sup.1H NMR (CDCl.sub.3) 8.44 (br t,
2), 8.18 (d, 4, J=8.7), 8.03 (br s, 2), 7.57 (d, 4, J=8.5), 4.78
(br m, 6), 3.46-3.42 (br q, 4), 3.36-3.30 (br m, 4), 1.39 (s, 18);
RP-LC/MS (ESI) m/z 753.2 (M+H).sup.+, 775.1 (M+Na).sup.+
(t.sub.R=4.02 min, 50-95% B). Anal. Calcd for
C.sub.34H.sub.44N.sub.10O.sub.10: C, 54.25; H, 5.89; N, 18.61.
Found: C, 54.20; H, 5.97; N, 18.32.
F.
3,6-Bis(cyclohexylamino)-N.sup.2,N.sup.5-bis[2-(tert-butoxycarbonyl)ami-
noethyl]pyrazine-2,5-dicarboxamide (12)
##STR00018##
[0160] To a partially-dissolved yellow suspension of
3,6-Diamino-N.sup.2,N.sup.5-bis[2-(tert-butoxycarbonyl)aminoethyl]pyrazin-
e-2,5-dicarboxamide (0.121 g, 0.250 mmol).sup.8 in anhyd DCE (10
mL), cyclohexanone (0.104 mL, 1.00 mmol) was added, and the
reaction flask was immersed in an ice bath. Then HOAc (0.058 mL,
1.00 mmol) was added followed by the addition of sodium
triacetoxyborohydride (0.212 g, 1.00 mmol) in small portions over a
10 min period. The resulting suspension was slowly allowed to warm
to r.t. and stirred overnight (ca. 17 h; RP-LC/MS analysis
indicated intact substrate) in an atmosphere of N.sub.2. At this
stage, the reaction mixture was treated with more cyclohexanone
(0.104 mL, 1.00 mmol), HOAc (0.058 mL, 1.00 mmol), and sodium
triacetoxyborohydride (0.212 g, 1.00 mmol) as described above, and
the reaction was continued for 48 h (RP-LC/MS analysis indicated
small amounts of substrate). Similar quantities of the reagents
were added once again and the reaction was continued over the
weekend (RP-LC/MS analysis indicated a complete reaction). After
the usual work up described in Example 2, the crude product (0.456
g) obtained was subjected to flash chromatography over silica gel
[CHCl.sub.3 to CHCl.sub.3-EtOAc (17:3, v/v)] to afford Example 6
(0.075 g, 46%) as a crimson red powder: R.sub.f 0.58
[CHCl.sub.3-EtOAc (7:3, v/v)]; .sup.1H NMR (CDCl.sub.3) 8.02 (br t,
2), 7.75 (d, 2, J=7.7), 4.83 (br t, 2), 3.90-3.76 (br m, 2), 3.52
(q, 4, J=5.9), 3.34 (q, 4, J=5.9), 2.02-1.20 (m, 38, includes Boc
singlet at .delta. 1.42); .sup.13C NMR (CDCl.sub.3) 166.51, 156.35,
144.79, 125.75, 79.42, 48.90, 40.36, 39.52, 32.82, 28.27, 25.92,
24.58; RP-LC/MS (ESI) m/z 647.5 (M+H).sup.+ (t.sub.R=5.36 min,
30-95% B). MS (ESI) m/z caled for C.sub.32H.sub.55N.sub.8O.sub.6
(M+H).sup.+647.4239, found 647.4238.
[0161] The byproducts of the reaction, 0.040 g (27%) of
3-(cyclohexylamino)-6-(ethylamino)-N.sup.2,N.sup.5-bis[2-(tert-butoxycarb-
onyl)aminoethyl]pyrazine-2,5-dicarboxamide [.sup.1H NMR
(CDCl.sub.3) 8.16 (br t, 1), 8.01 (br t, 1), 7.79 (d, 1, J=7.7),
7.63 (t, 1, J=5.1), 4.83 (br s, 2), 3.83 (br m, 1), 3.55-3.34 (m,
10), 1.99-1.21 (m, 31, include Boc singlet at .delta. 1.42 and Me
triplet at .delta. 1.27); RP-LC/MS (ESI) m/z 593.4 (M+H).sup.+
(t.sub.R=4.88 min, 30-95% B)] and 0.010 g (7%) of
3,6-bis(ethylamino)-N.sup.2,N.sup.5-bis[2-(tert-butoxycarbonyl)am-
inoethyl]pyrazine-2,5-dicarboxamide [.sup.1H NMR (CDCl.sub.3) 8.17
(br t, 2), 7.67 (t, 2, J=5.0), 4.86 (br t, 2), 3.55-3.33 (m, 12),
1.42 (s, 18), 1.27 (t, 6, J=7.2); RP-LC/MS (ESI) m/z 539.3
(M+H).sup.+, 561.5 (M+Na).sup.+ (t.sub.R=4.34 min, 30-95% B)], were
also isolated in the above chromatography.
G. Dimethyl
4,4'-[3,6-bis{2-(tert-butoxycarbonylamino)ethylcarbamoyl}pyrazine-2,5-diy-
l]bis(azanediyl)dibutanoate (13)
##STR00019##
[0163] The reaction of
3,6-Diamino-N.sup.2,N.sup.5-bis[2-(tert-butoxycarbonyl)aminoethyl]pyrazin-
e-2,5-dicarboxamide (0.965 g, 2.00 mmol).sup.8 with methyl
4-oxobutanoate (0.838 mL, 8.00 mmol) in the presence of HOAc (0.460
mL, 7.98 mmol) and sodium triacetoxyborohydride (1.70 g, 8.00 mmol)
in DCE (40 mL) was carried out overnight (ca. 20 h) as described in
the preparation of Example 2. After the usual work up, the orange
crude product (1.74 g) was subjected to flash chromatography over
silica gel [CHCl.sub.3-EtOAc (7:3, v/v)] to give Example 7 (1.30 g,
95%) as an orange-red powder: R.sub.f 0.33 [CHCl.sub.3-EtOAc (1:1,
v/v)]; .sup.1H NMR (CDCl.sub.3) 8.66 (t, 2, J=5.9), 7.93 (t, 2,
J=6.0), 5.21 (br t, 2), 3.67 (s, 6),3.56 (q, 4,J=5.8), 3.46-3.30
(m, 8), 2.42 (t, 4, J=6.5), 1.99-1.89 (quintet, 4), 1.41 (s, 18);
.sup.13C NMR (CDCl.sub.3) 174.40, 166.70, 156.00, 145.63,
126.09,79.17, 51.82,40.81, 40.39, 39.53, 30.89, 28.43, 24.44;
RP-LC/MS (ESI) m/z 683.3 (M+H).sup.+, 705.3 (M+Na).sup.+
(t.sub.R=4.75 min, 15-95% B). MS (ESI) m/z calcd for
C.sub.30H.sub.51N.sub.8O.sub.10 (M+H).sup.+ 683.3723, found
683.3719.
H.
3,6-Bis[2-(tert-butoxycarbonylamino)ethylamino]-N.sup.2,N.sup.5-bis[2-(-
tert-butoxycarbonyl)aminoethyl]pyrazine-2,5-dicarboxamide (14)
##STR00020##
[0165] To a partially-dissolved yellow suspension of
3,6-Diamino-N.sup.2,N.sup.5-bis[2-(tert-butoxycarbonyl)aminoethyl]pyrazin-
e-2,5-dicarboxamide (0.483 g, 1.00 mmol).sup.8 in anhyd DCE (20
mL), N-Boc-2-aminoacetaldehyde (0.382 g, 2.40 mmol) was added, and
the reaction flask was immersed in an ice bath. Then HOAc (0.120
mL, 2.08 mmol) was added followed by the addition of sodium
triacetoxyborohydride (0.636 g, 3.00 mmol) in small portions over a
15 min period. The resulting reddish suspension was slowly allowed
to warm to r.t. and stirred overnight (ca. 16 h; RP-LC/MS analysis
indicated some substrate) in an atmosphere of argon. At this stage,
the reaction mixture was treated with more
N-Boc-2-aminoacetaldehyde (0.191 g, 1.20 mmol), HOAc (0.120 mL,
2.08 mmol), and sodium triacetoxyborohydride (0.212 g, 1.00 mmol)
as described above, and the reaction was continued overnight (ca.
25 h; RP-LC/MS analysis indicated a complete reaction). After the
usual work up described in Example 2, the crude product (1.04 g)
obtained was subjected to flash chromatography over silica gel
[CHCl.sub.3-EtOAc (1.1, v/v)] to furnish Example 8 (0.813 g,
quantitative) as brick-red solid: R.sub.f 0.27; .sup.1H NMR
(DMSO-d.sub.6) 8.81 (t, 2, J=5.9), 7.95 (t, 2, J=5.9), 6.96 (t, 2,
J=5.6), 6.86 (br t, 2, J=5.1), 3.41 (q, 4, J=6.4), 3.35 (q, 4,
J=6.2), 3.15-3.08 (quintet, 8), 1.38 (s, 18), 1.35 (s, 18);
.sup.13C NMR (DMSO-d.sub.6) 165.43, 155.79, 155.50, 145.03, 125.70,
77.67, 77.52, 40.24 (overlaps with solvent), 39.05 (overlaps with
solvent); RP-LC/MS (ESI) m/z 769.3 (M+H).sup.+, 791.3 (M+Na).sup.+
(t.sub.R=5.10 min, 15-95% B). HRMS (ESI) m/z calcd for
C.sub.34H.sub.61N.sub.10O.sub.10 (M+H).sup.+ 769.4567, found
769.4567.
I.
3,6-Bis[3-(benzyloxycarbonylamino)propylamino]-N.sup.2,N.sup.5-bis[2-(b-
enzyloxycarbonyl)aminoethyl]pyrazine-2,5-dicarboxamide (16)
##STR00021##
[0167] Step 1. Synthesis of
3,6-Diamino-N.sup.2,N.sup.5-bis[2-(benzyloxycarbonyl)aminoethyl]pyrazine--
2,5-dicarboxamide (15).
##STR00022##
[0168] A suspension of N-carbobenzoxy-1,2-diaminoethane
hydrochloride (4.61 g, 20.0 mmol) in anhyd DMF (100 mL) was stirred
with DIPEA (3.50 mL, 20.1 mmol) for 30 min in an atmosphere of
N.sub.2. Then 3,6-diaminopyrazine-2,5-dicarboxylic acid (1.98 g,
10.0 mmol) was added, and after 15 min, HOBt.H.sub.2O (3.37 g, 22.0
mmol) and EDC.HCl (4.22 g, 22.0 mmol) were added, and the resulting
dark suspension was stirred at r.t. overnight (ca. 16 h). Most of
the DMF was removed under high vacuum and the slurry was stirred
with anhyd Et.sub.2O-MeOH (1:3, v/v; 200 mL) for about 30 min. The
precipitate was collected by filtration and thoroughly washed with
MeOH and anhyd Et.sub.2O and dried under high vacuum to give the
bisamide 15 (4.37 g, 79%) as a yellow powder: .sup.1H NMR
(DMSO-d.sub.6) 8.50 (t, 2, J=5.5), 7.39-7.31 (m, 10), 6.50 (br s,
4), 5.02 (s, 4), 3.37-3.34 (br q, 4), 3.20-3.17 (br q, 4); .sup.13C
NMR (DMSO-d.sub.6) 165.80, 156.74, 146.65, 137.60, 128.78, 128.22,
128.20, 126.83, 65.74, 40.44 (overlaps with solvent), 39.22
(overlaps with solvent); RP-LC/MS (EST) m/z 551.2 (M+H).sup.+,
573.2 (M+Na).sup.+ (t.sub.R=3.86 min, 25-95% B). Anal. Calcd for
C.sub.26H.sub.30N.sub.8O.sub.6: C, 56.72; H, 5.49, N, 20.35. Found:
C, 56.79; H, 5.49; N, 20.30.
[0169] Step 2. To a yellow suspension of the above bisamide 15
(1.10 g, 2.00 mmol) in anhyd DCE (50 mL),
3-[(benzyloxycarbonyl)amino]propionaldehyde (1.24 g, 6.00 mmol) was
added, and the reaction flask was immersed in an ice bath. Then
HOAc (0.340 mL, 5.90 mmol) was added followed by the addition of
sodium triacetoxyborohydride (1.27g, 6.00 mmol) in small portions
over a 30 min period. The resulting reddish suspension was slowly
allowed to warm to r.t. and stirred overnight (ca. 40 h; RP-LC/MS
analysis indicated some substrate) in an atmosphere of N.sub.2. At
this stage, the reaction mixture was diluted with anhyd DCE (30 mL)
and treated with more 3-[(benzyloxycarbonyl)amino]propionaldehyde
(0.414 g, 2.00 mmol), HOAc (0.12 mL, 2.08 mmol), and sodium
triacetoxyborohydride (0.424 g, 2.00 mmol) as described above, and
the reaction was continued over the weekend (RP-LC/MS analysis
indicated only traces of substrate). After the usual work up
described in Example 2, the crude product obtained was suspended in
CH.sub.3CN-anhyd Et.sub.2O (1:1, v/v; 100 mL) and stirred at r.t.
for 30 min. The precipitate was collected by filtration, washed
with CH.sub.3CN-anhyd Et.sub.2O, and dried under high vacuum to
give Example 9 (1.35 g) as an orange-red powder. The filtrate was
concentrated and subjected to flash chromatography over silica gel
[CHCl.sub.3-MeOH (49: 1, v/v)] to obtain additional 0.09 g of the
product, bringing the overall yield to 1.44 g (77%): R.sub.f 0.42
[CHCl.sub.3-MeOH (19:1, v/v)]; .sup.1H NMR (DMSO-d.sub.6) 8.53 (t,
2, J=5.5), 7.86 (br t, 2), 7.42 (t, 2, J=5.5), 7.36-7.21 (m, 20),
4.99 (s, 4), 4.98 (s, 4), 3.50-3.30 (m, 10), 3.18 (q, 4,J=6.1),
3.07 (q, 4, J=6.4), 1.66 (quintet, 4); RP-LC/MS (ESI) m/z 933.4
(M+H).sup.+ (t.sub.R=4.96 min, 15-95% B). Anal. Calcd for
C.sub.42H.sub.68N.sub.8O.sub.12: C, 61.79; H, 6.05; N, 15.01.
Found: C, 61.53; H, 5.92; N, 14.96.
J. Diethyl 3,6-bis(2-methoxyethylamino)pyrazine-2,5-dicarboxylate
(17)
##STR00023##
[0171] The reaction of diethyl
3,6-diaminopyrazine-2,5-dicarboxylate (0.127 g, 0.500 mmol).sup.2
with methoxyacetaldehyde (0.148 g, 2.00 mmol) in the presence of
HOAc (0.115 mL, 2.00 mmol) and sodium triacetoxyborohydride (0.424
g, 2.00 mmol) in DCE (20 mL) was carried out as described in the
preparation of Example 1. However, it should be mentioned here that
the second batch of reagents were added after 21 h and the overall
duration of the reaction was 68 h. After the usual work up, the red
crude product (0.210 g) was subjected to flash chromatography over
silica gel [CH.sub.2Cl.sub.2 to CH.sub.2Cl.sub.2-EtOAc (9:1, v/v)]
to afford Example 10 (0.075 g, 41%) as a maroon solid: R.sub.f 0.29
[CHCl.sub.3-EtOAc (19:1, v/v)]; .sup.1H NMR (CDCl.sub.3) 7.31 (t,
2, J=5.3), 4.39 (q, 4, J=7.1), 3.69-3.60 (m, 8), 3.41 (s, 6), 1.41
(t, 6, J=7.1); .sup.13C NMR (CDCl.sub.3) 166.28, 147.48, 125.54,
71.41, 61.58, 58.76, 40.68, 14.14; RP-LC/MS (ESI) m/z 371.2
(M+H).sup.+, 393.2 (M+Na).sup.+ (t.sub.R=4.59 min, 15-95% B).
K.
3,6-Bis(38-oxo-2,5,8,11,14,17,20,23,26,29,32,35-dodecaoxa-39-azahente-t-
racontan-41-ylamino)-N.sup.2,N.sup.5-bis(38-oxo-2,5,8,11,14,17,20,23,26,29-
,32,35-dodecaoxa-39-azahentetracontan-41-yl)pyrazine-2,5-dicarboxamide
(18)
##STR00024##
[0173] Compound 18, above, is a longer wavelength compound
(excitation .about.500 nm, emission .about.600 nm orange). To
achieve the red shift in both excitation and emission wavelengths,
electron donation into the ring was increased by alkyl substitution
on the pyrazine ring nitrogens. The synthetic strategy for these
longer wavelength analogues involves functionalizing the carboxyls
first through amide chemistry described above followed by reductive
amination of the pyrazine amino groups. Thus the synthesis of
compound 18, above, is presented below. MP-3064 was coupled with
Boc-ethylenediamine using the EDC method to afford MP-3183. This
material was then converted to MP-3216 by reductive amination using
Boc-2-aminoacetaldehyde and sodium triacetoxyborohydride. MP-3216
was purified by flash chromatography and deprotected with TFA to
afford the corresponding tetramine salt. This material was then
acylated with NHS-m-dPEG.sub.12 and purified by HPLC to afford
compound 18:
##STR00025##
[0174] A mixture of sodium 3,6-diaminopyrazine-2,5-dicarboxylate
(500 mg, 2.07 mmol), tert-butyl 2-aminoethylcarbamate (673 mg, 4.20
mmol), HOBt-H.sub.2O (836 mg, 5.46 mmol) and EDC-HCl (1.05 g, 5.48
mmol) in DMF (25 mL) was stirred for 16 h and concentrated. The
residue was partitioned with 1N NaHSO.sub.4 (200 mL) and EtOAc (200
mL). The layers were separated and the organic was washed with
water (200 mL), sat. NaHCO.sub.3 (200 mL) and brine (200 mL). The
EtOAc solution was dried (Mg.sub.2SO.sub.4), filtered and
concentrated to afford 770 mg (76% yield) of
3,6-diamino-N.sup.2,N.sup.5-bis(2-(tert-butoxy
carbonylaminoethyl))pyrazine-2,5-dicarboxamide (MP-3183) as an
orange foam: .sup.1NMR (300 MHz, DMSO-d.sub.6) major comformer,
.delta. 8.44 (t, J 5.7 Hz, 2 H), 6.90 (t, J=5.7 Hz, 2 H), 6.48 (bs,
4 H), 2.93-3.16 (complex m, 8 H), 1.37 (s, 9 H), 1.36 (s, 9 H).
.sup.13C NMR (75 MHz, DMSO-d.sub.6), conformational isomers .delta.
165.1 (s), 155.5 (bs), 155.4 (bs), 146.0 (s), 126.2 (s), 77.7 (bs),
77.5 (bs), 45.2 (bt), 44.5 (bt), 28.2 (q). LCMS (15-95% gradient
ACN in 0.1% TFA over 10 min), single peak retention time=7.18 min
on 30 mm column, (M+H).sup.+=483.
[0175] To a partially-dissolved yellow suspension of MP-3183 (0.483
g, 1.00 mmol) in anhydrous DCE (20 mL), N-Boc-2-aminoacetaldehyde
(0.382 g, 2.40 mmol) was added, and the reaction flask was immersed
in an ice bath. Then HOAc (0.120 mL, 2.08 mmol) was added followed
by the addition of sodium triacetoxyborohydride (0.636 g, 3.00
mmol) in small portions over a 15 min period. The resulting reddish
suspension was slowly allowed to warm to room temperature and
stirred overnight (ca. 16 h; LC/MS analysis indicated some
substrate). At this stage, the reaction mixture was treated with
more N-Boc-2-aminoacetaldehyde (0.191 g, 1.20 mmol), HOAc (0.120
mL, 2.08 mmol), and sodium triacetoxyborohydride (0.212 g, 1.00
mmol) as described above, and the reaction was continued overnight
(ca. 25 h; RP-LC/MS analysis indicated a complete reaction). The
reaction was quenched by a slow addition of sat. NaHCO.sub.3 (30
mL) at 0.degree. C. The biphasic mixture was stirred for 30 min and
extracted with CHCl.sub.3 (3.times.40 mL). The combined organic
extracts were washed with H.sub.2O and brine (50 mL each). Removal
of the solvent gave 1.04 g of a red solid, which upon flash
chromatography over silica gel [CHCl.sub.3-EtOAc (1:1, v/v)]
afforded WP-3216 (0.813 g, quantitative) as brick-red solid:
R.sub.f 0.27; .sup.1H NMR (DMSO-d.sub.6) .delta. 8.81 (t, 2,
J=5.9), 7.95 (t, 2, J=5.9), 6.96 (t, 2, J=5.6), 6.86 (br t, 2,
J=5.1), 3.41 (q, 4, J=6.4), 3.35 (q, 4, J=6.2), 3.15-3.08 (quintet,
8), 1.38 (s, 18), 1.35 (s, 18); .sup.13C NMR (DMSO-d.sub.6) .delta.
165.43, 155.79, 155.50, 145.03, 125.70, 77.67, 77.52, 40.24
(overlaps with solvent), 39.05 (overlaps with solvent); LCMS (ESI)
m/z 769.3 (M+H).sup.+, 791.3 (M+Na).sup.+ (t.sub.R=5.10 min, 15-95%
B). ERMS (ESI) m/z calcd for C.sub.34H.sub.61N.sub.10O.sub.10
(M+H).sup.+ 769.4567, found 769.4567.
[0176] To a red suspension of MP-3216 (0.769 g, 1.00 mmol) in anhyd
CH.sub.2C1.sub.2 (15 mL), was added TFA (15 mL) carefully while
stirring at ice-bath temperature. The reaction became homogeneous
instantaneously with a pale yellow coloration, and then turned red
after a few minutes. After 30 min at 0.degree. C., the cooling bath
was removed, and the reaction continued for 1.5 h under N.sub.2
atmosphere. The reaction mixture was concentrated in vacuo, the
viscous residue was co-evaporated with CH.sub.2Cl.sub.2 (5.times.25
mL), and then dried overnight under high vacuum to give MP-3216-tfa
salt (0.886 g, 107% for tetra-TFA salt) as a reddish brown solid:
.sup.1H NMR (DMSO-d.sub.6) .delta. 8.75 (t, 2, J=6.1), 8.06 (br t,
2), 7.97 (br s, 4), 7.86 (br s, 4), 3.73 ( br q, 4), 3.55 (q, 4,
J=6.3), 3.04-2.95 (m, 8); RP-LC/MS (ESI) m/z 369.4 (M+H).sup.+,
737.4 (2M+H).sup.+ (t.sub.R=1.09 min, 5-95% ACN in H.sub.2O, 0.1%
TFA).
[0177] To a red solution of the MW-3216-tfa salt (0.543 g crude,
0.50 mmol) in DMF (8 mL), NMM (1.10 mL, 10.0 mmol) was added at
0.degree. C., and stirred for 30 min in an atmosphere of N.sub.2.
Then a solution of NHS-m-dPEG.TM..sub.12(7, 1.58 g, 2.30 mmol) in
CH.sub.2Cl.sub.2 (2 mL) was added and the reaction mixture was
stirred overnight (ca. 14 h) at ambient temperature. Most of the
solvents were removed under high vacuum and the red syrup was
subjected to preparative HPLC [column: Waters XBrdige.TM. Prep C18
OBD.TM. 5 .mu.m 10.times.150 mm; .lamda..sub.max: PDA (200-600 nm);
flow: 50 mL/min; gradient: 5-50% B/10 min (mobile phase A: 0.1% TEA
in H.sub.2O; mobile phase B: 0.1% TFA in CH.sub.3CN)] to give
MP-3217 (0.443 g, 33%) as a brick-red slush: .sup.1H NMR
(DMSO-d.sub.6) characteristic br s at .delta. 3.50 and s at .delta.
3.23 for poly(ethylene glycol) moiety; HPLC (254 nm) 89%
[t.sub.R=14.4 min, 20-80% ACN in H.sub.2O, 0.1% TFA over 20 min
(column: Phenomenex Luna 5 .mu.m C18(2) 100 .ANG. 250.times.4.6 mm;
flow. 1 mL/min; mobile phase A: 0.1% TFA in H.sub.2O; mobile phase
B: 0.1% TFA in CH.sub.3CN]; LC/MS (ESI) m/z 884.3 (M+3H).sup.3+,
1325.4 (M+2H).sup.2+ (t.sub.R=3.81 min, 5-95% B). HRMS (ESI) m/z
calcd for C.sub.118H.sub.231N.sub.10O.sub.54 (M+3H).sup.3+
884.1874, found 884.1872; calcd for
C.sub.118H.sub.230N.sub.10O.sub.54 (M+2H).sup.2+ 1325.7774, found
1325.7769.
Other Aspects and Embodiments
[0178] The detailed description set forth above is provided to aid
those skilled in the art in practicing the present invention.
However, the invention described and claimed herein is not to be
limited in scope by the specific aspects and embodiments herein
disclosed because these aspects and embodiments are intended as
illustration of several aspects of the invention. Any equivalent
aspects and embodiments are intended to be within the scope of this
invention. Indeed, various modifications of the invention in
addition to those shown and described herein will become apparent
to those skilled in the art from the foregoing description that do
not depart from the spirit or scope of the present inventive
discovery. Such modifications are also intended to fall within the
scope of the appended claims.
REFERENCES CITED
[0179] Citation of a reference herein shall not be construed as an
admission that such is prior art to the present invention.
[0180] [1] C. A. Rabito, L. S. T. Fang, and A. C. Waltman, "Renal
function in patients at risk with contrast material-induced acute
renal failure: Noninvasive real-time monitoring," Radiology 1993,
186, 851-854.
[0181] [2] N. L. Tilney, and J. M. Lazarus, "Acute renal failure in
surgical patients: Causes, clinical patterns, and care," Surgical
Clinics of North America 1983, 63, 357-377.
[0182] [3] B. E. VanZee, W. E. Hoy, and J. R. Jaenike, "Renal
injury associated with intravenous pyelography in non-diabetic and
diabetic patients," Annals of Internal Medicine 1978, 89,
51-54.
[0183] [4] S. Lundqvist, G. Edbom, S. Groth, U. Stendahl and S.-O.
Hietala, "Iohexol clearance for renal function measurement in
gynecologic cancer patients," Acta Radiologica 1996, 37,
582-586.
[0184] [5] P. Guesry, L. Kaufman, S. Orloff, J. A. Nelson, S.
Swann, and M. Holliday, "Measurement of glomerular filtration rate
by fluorescent excitation of non-radioactive meglumine
iothalamate," Clinical Nephrology 1975, 3, 134-138.
[0185] [6] C. C. Baker, L. Oppenheimer, and B. Stephens,
"Epidemiology of trauma deaths," American Journal of Surgery 1980,
140, 144-150.
[0186] [7] R. G. Lobenhoffer, and M. Grotz, "Treatment results of
patients with multiple trauma: An analysis of 3406 cases treated
between 1972 and 1991 at a German level I trauma center," Journal
of Trauma 1995, 38, 70-77.
[0187] [8] F. W. Dodge, B. L Travis, and C. N. Daeschner,
"Comparison of endogenous creatinine clearance with inulin
clearance," Am. J Dis. Child. 1967, 113, 683-692.
[0188] [9] J. Brochner-Mortensen, J. Giese, N. Rossing, "Renal
inulin clearance versus total plasma clearance of .sup.51Cr-EDTA,"
Scand. J. Clin. Lab. Invest. 1969, 23, 301-303.
[0189] [10] C. White, A. Akbari, N. Hussain, L. Dinh, G. Filler, N.
Lepage, and G. Knoll, "Estimating glomerular filtration rate in
kidney transplantation: A comparison between serum creatinine and
cystatin C-based methods," J. Am. Soc. Nephrol, 2005, 16, 3763-3770
and references cited therein.
[0190] [11] P. L. Choyke, H. A. Austin, J. A. Frank, "Hydrated
clearance of gadolinium-DTPA as a measurement of glomerular
filtration rate," Kidney International 1992, 41, 1595-1598.
[0191] [12] M. F. Tweedle, X. Zhang, M. Fernandez, P. Wedeking, A.
D. Nunn, and H. W. Strauss, "A noninvasive method for monitoring
renal status at the bedside," Invest. Radiol. 1997, 32,
802-805.
[0192] [13] N. Lewis, R. Kerr, C. Van Buren, "Comparative
evaluation of urographic contrast media, inulin, and
.sup.99mTc-DTPA clearance methods for determination of glornerular
filtration rate in clinical transplantation," Transplantation 1989,
48, 790-796.
[0193] [14] R. Muller-Suur, C. Muller-Suur, "Glomerular filtration
and tubular secretion of MAG.sub.3 in rat kidney," Journal of
Nuclear Medicine 1989, 30, 1986-1991.
[0194] [15] Sekar, N. Pyrazine dyes: An update. Colourage 1999,
41-44.
[0195] [16] Shirai, K.; Yanagisawa, A.; Takahashi, H.; Fukunishi,
K.; Matsuoka, M. "Syntheses and fluorescent properties of
2,5-diamino-3,6-dicyanopyrazine dyes," Dyes and Pigments 1998, 39,
49-68.
[0196] [17] Kim, J. H.; Shin, S. R.; Matsuoaka, M.; Fukunishi, K.
"Self-assembling of aminopyrazine fluorescent dyes and their solid
state spectra," Dyes and Pigments 1998, 39, 341-357.
[0197] [18] Kim, J. H.; Shin, S. R.; Matsuoaka, M.; Fukunishi, K.
Self-assembling of aminopyrazine fluorescent dyes and their solid
state spectra, Part 2. Dyes and Pigments 1999, 41, 183-191.
[0198] [19] F. Roch-Ramel, K. Besseghir, and H. Murer. Renal
excretion and tubular transport of organic anions and cations. In
Handbook of Physiology, Section 8, Neurological Physiology, Vol II,
E. E. Windhager, Editor, pp. 2189-2262. Oxford University Press:
New York, 1992
[0199] [20] F. Roch-Ramel and M. E. De Broe, Chapter 2, "Renal
handling of drugs and xenobiotics," in Clinical Nephrotoxins: Renal
Injury from Drugs and Chemicals, M. E. De Broe, G. Porter, W.
Bennett, G. Verpooten Eds., pp 21-46, Kluwer Academic Publishers,
Dordrecht, The Netherlands, 2003.
[0200] [21] Yamaoka, T., Tabata, Y., Ikada, Y. J. Pharm. Sci. 1994,
83, 601.
[0201] [22] Muller et al. Eds, Medical Optical Tomography, SPIE
Volume IS11, 1993.
[0202] [23] R. B. Dorshow et al. Non-Invasive Fluorescence
Detection of Hepatic and Renal Function, Bull. Am. Phys. Soc. 1997,
42, 681.
* * * * *