U.S. patent application number 12/767154 was filed with the patent office on 2010-08-12 for dendritic compound and use thereof.
This patent application is currently assigned to Industrial Technology Research Institute. Invention is credited to Hui-Ju CHO, Abraham JOSEPHK, Chao-Hung KAO, Huang-Chien LIANG, Yu-Hau SHIH.
Application Number | 20100204508 12/767154 |
Document ID | / |
Family ID | 36696967 |
Filed Date | 2010-08-12 |
United States Patent
Application |
20100204508 |
Kind Code |
A1 |
JOSEPHK; Abraham ; et
al. |
August 12, 2010 |
DENDRITIC COMPOUND AND USE THEREOF
Abstract
A dendritic compound of the following structure: PD.sub.n-Z-L is
disclosed. In the structure above, P is
X--(CH.sub.2CH.sub.2--O).sub.r--, r is an integer ranging from 1000
to 4000, X is OH, NH.sub.2, or OR, R is C.sub.1 to C.sub.10 alkyl,
D.sub.n is a residue of branched C.sub.3 to C.sub.30 polyol
compounds, n is the quantity of layers of the residue of branched
compounds and is an integer equal to or greater than 1, L is a
metal cation, Z is the residue of a C.sub.3 to C.sub.30 compound
with multi functional groups. The functional groups illustrated
above can be carboxylic groups, amino groups, amide groups, or
chelating groups. The carboxylic groups, ester groups, amino
groups, or amide groups bind to D.sub.n, and the chelating groups
bind to the metal cations.
Inventors: |
JOSEPHK; Abraham; (Hsinchu
City, TW) ; CHO; Hui-Ju; (Lugang Township, TW)
; SHIH; Yu-Hau; (Sindian City, TW) ; KAO;
Chao-Hung; (Taipei City, TW) ; LIANG;
Huang-Chien; (Hsinchu City, TW) |
Correspondence
Address: |
BACON & THOMAS, PLLC
625 SLATERS LANE, FOURTH FLOOR
ALEXANDRIA
VA
22314-1176
US
|
Assignee: |
Industrial Technology Research
Institute
Hsinchu
TW
|
Family ID: |
36696967 |
Appl. No.: |
12/767154 |
Filed: |
April 26, 2010 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11316822 |
Dec 27, 2005 |
7732558 |
|
|
12767154 |
|
|
|
|
Current U.S.
Class: |
560/196 ;
560/198 |
Current CPC
Class: |
A61K 49/124
20130101 |
Class at
Publication: |
560/196 ;
560/198 |
International
Class: |
C07C 69/34 20060101
C07C069/34 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 30, 2004 |
TW |
093141379 |
Claims
1. A dendritic compound of following structure (I); PD.sub.n-Z-L
(I) wherein, P is X--(CH.sub.2CH.sub.2--O).sub.r--, r is an integer
equal to 1 or greater than 1, X is OH, NH.sub.2 or OR, and R is
C.sub.1 to C.sub.10 alkyl; D.sub.n is a residue of branched C.sub.3
to C.sub.30 polyol compounds, n is the quantity of layers of the
residue of branched compounds and n is an integer equal to or
greater than 1; L is metal cations; and Z is the residue of a
C.sub.3 to C.sub.30 compounds with multi functional groups;
wherein, the functional groups are carboxylic groups, amino groups,
ester groups, amide groups, or chelating groups; and the carboxylic
groups, ester groups, amino groups, or amide groups bound to Dn,
and the chelating groups bind to the metal cations.
2. The dendritic compound as claimed in claim 1, wherein P is poly
ethylene glycol.
3. The dendritic compound as claimed in claim 1, wherein Dn is a
residue of 2,2-bis(hydroxymethyl)propionic acid or the derivatives
thereof.
4. The dendritic compound as claimed in claim 3, wherein Dn is
D.sub.1 having a structure of formula (I): ##STR00005##
5. The dendritic compound as claimed in claim 3, wherein Dn is
D.sub.2 having a structure of formula (II): ##STR00006##
6. The dendritic compound as claimed in claim 3, wherein Dn is
D.sub.3 having a structure of formula (III): ##STR00007##
7. The dendritic compound as claimed in claim 1, wherein the L is a
metal ion having a feature of exposure.
8. The dendritic compound as claimed in claim 7, wherein L is
Gadolinium (Gd).
9. The dendritic compound as claimed in claim 7, wherein Z is a
residue of ethylenedinitrilo tetraacetic acid (EDTA), or
ethylenediimino dibyric acid (EDBA).
10. The dendritic compound as claimed in claim 9, wherein Z is the
structure of formula (IV): ##STR00008##
11. The dendritic compound as claimed in claim 10, wherein L is
Gadolinium (Gd), and P is polyethylene glycol.
12. The dendritic compound as claimed in claim 6, wherein L is
Gadolinium (GD) and P is polyethylene glycol.
13. The dendritic compound as claimed in claim 1 exhibiting high
contrast when used as an imaging agent in MRI imaging.
14. A dendritic compound of following structure (I): PD.sub.n-Z-L
(I) wherein, P is X--(CH.sub.2CH.sub.2--O).sub.r--, r is an integer
equal to 1 or greater than 1, X is OH, NH.sub.2 or OR, and R is
C.sub.1 to C.sub.10 alkyl; D.sub.n is a residue of branched C.sub.3
to C.sub.30 polyol compounds, n is the quantity of layers of the
residue of branched compounds and n is an integer equal to or
greater than 1; L is metal cations; and Z is a residue of
ethylenedinitrilo tetraacetic acid (EDTA), ethylenediimino dibyric
acid (EDBA), or a compound of formula (IV): ##STR00009##
15. The dendritic compound according to claim 14, wherein Z is
EDTA.
16. The dendritic compound according to claim 14, wherein Z is
EDBA.
17. The dendritic compound according to claim 14, wherein z is a
compound having the structure of formula (IV): ##STR00010##
18. The dendritic compound as claimed in claim 14, wherein L is a
metal ion having a feature of exposure.
19. A dendritic compound of following structure (I): PD.sub.n-Z-L
(I) wherein, P is X--(CH.sub.2CH.sub.2--O).sub.r--, r is an integer
equal to 1 or greater than 1, X is OH, NH.sub.2 or OR, and R is
C.sub.1 to C.sub.10 alkyl; D.sub.n is a branched C.sub.3 to
C.sub.30 polyol compound, n is an integer equal to or greater than
1 and is the quantity of layers of the branched compound that are
present; L is Gadolinium (Gd); and Z is ethylenedinitrilo
tetraacetic acid (EDTA), ethylenediimino dibyric acid (EDBA), or a
compound having the structure of formula (IV): ##STR00011##
Description
[0001] This application is a continuation application of pending
U.S. patent application Ser. No. 11/316,822 filed Dec. 27, 2005 (of
which the entire disclosure of the pending, prior application is
hereby incorporated by reference).
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a dendritic compound, and
more particularly, to a dendritic compound suitable for chelating
with metal cations.
[0004] 2. Description of Related Art
[0005] Nuclear Magnetic Resonance Imaging (MRI) is one of the most
significant diagnosing techniques in modern medical science.
Compared to X-rays or CT scanning, MRI provides multi-angle
scanning which can be applied to the central nerve system, the
skeletal nerve system, the abdomen, the chest, angiography,
cholangiography, and the most important and valuable of all, to
discover and diagnose tumor tissues.
[0006] The principle of MRI is to transform the hydrogen atoms
within human tissues into tiny radio transmitters. Under the same
magnetic field change, hydrogen atoms within water or other
molecules transmit different signals. MRI traces these signals and
forms the 3-D image of a human body through Fourier Transfer. In
other words, the greater the differences in each radio-transmitted
signal, the clearer contrast will be transformed. So far, it is
known that the use of super-paramagnetic elements, such as
Gadolinium (Gd), can enhance the contrast. As a result, the density
of super-paramagnetic elements is the critical factor for the
clarity of image.
[0007] In addition, due to the fact that free Gd is toxic, a
chelator must be added when the Gd is applied to human bodies. The
addition of the chelator can decrease the chemical reaction during
body circulation. Diethylenetriamine pentaacetic acid (DTPA) is one
of the most common and commercially mass produced chelators for
application in MRI.
[0008] However, when applying the commercialized non-polymer
carrier Gd-DTPA as an imaging agent, chelators with small molecule
weight penetrate vascular endothelial cells easily and thus
extensive losses occur while circulating. Furthermore, it requires
high concentration of Gd to achieve the desirable image. In
addition to the potential danger of toxicity caused by high
concentration of Gd, it is also difficult to massively accumulate
an imaging agent on a certain position. Therefore, there exists a
great disadvantage for clinical application of prior art
non-polymer Gd-DTPA imaging agents.
SUMMARY OF THE INVENTION
[0009] The present invention provides a dendritic compound of the
following structure (I):
PD.sub.n-Z-L (I)
[0010] wherein,
[0011] P is X--(CH.sub.2CH.sub.2--O).sub.r--, r is an integer equal
to 1 or greater than 1, X is OH, NH.sub.2 or OR, and R is C.sub.1
to C.sub.10 alkyl;
[0012] D.sub.n is a residue of branched C.sub.3 to C.sub.30 polyol
compounds, n is the quantity of layers of the residue of branched
compounds and n is an integer equal to or greater than 1;
[0013] L is metal cations; and
[0014] Z is the residue of a C.sub.3 to C.sub.30 compounds with
multi functional groups;
[0015] wherein, the functional groups are carboxylic groups, amino
groups, ester groups, amide groups, or chelating groups; and the
carboxylic groups, ester groups, amino groups, or amide groups
bound to Dn, and the chelating groups bound to the metal
cations.
[0016] The dendritic compound of the present invention can be any
conventional poly ethylene glycol derivative, but preferably is
poly ethylene glycol. D.sub.n in the dendritic compound of the
present invention can be any residue of C.sub.3 to C.sub.30
branched polyol compounds, but preferably is
2,2-bis(hydroxymethyl)propionic acid or the residue of its
derivatives, DTPA residue, residue of DTPA derivatives, or the
combination thereof.
[0017] Furthermore, the quantity of layers (n) of the dendritic
compound of the present invention is not limited, but preferably
n=3. L in the dendritic compound of the present invention can be
any metal ion with biological toxicity, but preferably is Gd.
Finally, Z can be any residue of C.sub.3-C.sub.20 compounds with
multiple functional groups, but preferably is residue of
ethylenedinitrilo tetraacetic acid (EDTA), or that of
ethylenediimino dibyric acid (EDBA). The more preferable is the
residue of the compound having the structure of formula (IV)
below.
##STR00001##
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] In this invention, linear polyethylene glycol and
2,2-bis(hydroxymethyl)propionic anhydride are used as starting
materials. Diethylenetriaminepentacetic acid (DTPA) is the chelator
to stabilize Gd.
Example 1
Preparation of Dendritic Compound P-D.sub.1-(DTPA)
[0019] a. Preparation of the First Generation Benzylidene Protected
Chelate P-D.sub.1-(O.sub.2Bn)
[0020] PEG diol (MW 4000 Da, 9.2 g, 2.3 mmol, 1 eq) and DMAP
(0.1670 g, 0.39 mmol) are mixed in a round-bottom conical vial. The
mixture is dissolved in a 25 mL of DCM and then the vial is filled
with nitrogen gas. Benzylidene-2,2-bis(oxymethyl) propionic
anhydride (4.27 g (10 mmol)) is dissolved in another vial, and then
slowly dripped into the reaction vial. After 24 hours of stirring
and reacting in room temperature, 10 ml methanol is added and the
reaction is kept for another 6 hours for removing the un-reacted
Benzylidene-2,2-bis(oxymethyl) propionic anhydride. An excessive
amount of ethyl ether (700 mL) is added and the mixture is stirred
until white precipitates are released, and the yield rate is about
90%. Among the products, the D.sub.n is D.sub.1 with the structure
of (I) as follows:
##STR00002##
[0021] IR (cm-I): 2890, 1738, 1150.
[0022] .sup.1H NMR (400 MHz, CDCl.sub.3): .delta. 1.06 (s, 6), 3.55
(t, 6), 3.61 (bs), 3.68 (t, 6), 4.32 (t, 4), 4.64 (d, 4), 5.43 (s,
2), 7.28 (m, 6), 7.42 (m, 4).
[0023] b. Preparation of Chelate P-D.sub.1-(OH)
[0024] After the above product (11.8 g) is dissolved in 40 mL of
1:2 CH.sub.2Cl.sub.2/MeOH solution, 1.18 g of Pd/C is added, and
the mixture is stirred for 24 hours under a hydrogen-saturated
environment. When the reaction ends, Pd/C is filtrated from DCM,
and as described above, an excessive amount of ethyl ether 600 (mL)
is added to release the white precipitates. The yield rate of the
product after freeze-drying is approximately 90%.
[0025] IR (cm-I): 3480, 2890, 1725, 1148.
[0026] .sup.1H NMR (400 MHz, CDCl.sub.3): .delta. 1.08 (s, 6), 3.67
(bs), 4.31 (t, 4).
[0027] c. Synthesis of P-D.sub.1-DTPA
[0028] P-D.sub.1-OH (2.0 g, 0.4618 mmol) and
diethylenetriaminepentaacetic acid mono-N-hydroxysuccinimide ester
(DTPA-HSIE) (1.0871 g, 2.2 mmol) are mixed in a 50 mL round-bottom
conical vial and vacuum dried for 3 hours. Anhydrous DMSO (10 mL)
and Triethylamine (224 .mu.L) are injected into the mixture and
stirred for 48 hours at room temperature under saturated nitrogen
gas. Acetonitrile/acetone is used to release white residue; the
white solid product after centrifugation and freeze-drying is
P-D.sub.1-DTPA.
[0029] IR (cm-1): 3446, 2888, 1714, 1638, 1109.
[0030] .sup.1H NMR (400 MHz, CDCl.sub.3): .delta. 1.14 (s, 6), 3.1
(t, 16), 3.4 (t, 16), 3.57 (bs), 3.75 (s, 8), 3.8 (s, 32).
Example 2
Preparation of Dendritic Compound P-D.sub.2-(ODTPA)
[0031] a. Preparation of Chelate P-D.sub.2-(O.sub.2Bn)
[0032] The principle of preparing the second generation
P-D.sub.2-(O.sub.2Bn) product is approximately the same as that of
the first generation. P-D.sub.1-(O.sub.2Bn) (95.6 g, 0.83 mmol, 1
equiv) and DMAP (0.326 g, 2.6 mmol, 3.2 equiv) is mixed and then
dissolved in 25 mL DCM. After Benzylidene-2,2-bis(oxymethyl)
propionic anhydride (13.3 mmol, 16 equiv, 5.69 g) is added, the
mixture is stirred at room temperature for 24 hours. Un-reacted
Benzylidene-2,2-bis (oxymethyl) propionic anhydride is removed with
15 mL Methanol. Then ethyl ether is used to release the white
precipitate at a yield rate of 80% after freeze-drying. The product
D.sub.n is D.sub.2 with the structure (II) as follows:
##STR00003##
[0033] IR (cm-I): 2885, 1740, 1100.
[0034] .sup.1H NMR (400 MHz, CDCl.sub.3): .delta. 1.03 (s, 12),
1.26 (s, 6), 3.63 (bs), 3.78 (t, 4), 4.03 (t, 4), 4.38 (s, 8), 4.56
(d, 8), 5.41 (s, 4), 7.19 (m, 12), 7.38 (m, 8).
b. Preparation of chelate P-D.sub.2-OH
[0035] The product (5.5 g) from the above process is dissolved in
45 mL of 1:2 DCM/MeOH solution. The de-protection procedure in step
b. of example 1 is repeated, and the final yield rate is about
88%
[0036] IR (cm-1): 3401, 2887, 1727, 1108.
[0037] .sup.1H NMR (400 MHz, CDCl.sub.3): .delta. 1.03 (s, 12),
1.19 (s, 6), 3.43 (m, 8), 3.64 (bs), 4.08 (m, 8), 4.40 (d, 4).
c. Synthesis of P-D.sub.2-DTPA
[0038] The method of synthesizing the second generation
P-D.sub.2-DTPA is approximately the same as that of first
generation. P-D.sub.2-OH (0.265 mmol, 1.3965 g) and 1.2482 g (2.54
mmol) DTPA-HSIE is mixed in a 50 mL round bottom conical vial and
vacuum dried for 4 hours. Anhydrous DMSO (10 mL) and 350 .mu.L
Triethylamine is injected into the mixture, and stirred for 48
hours at room temperature under saturated nitrogen gas.
Acetonitrile/acetone solution is used to release the white
precipitate, and P-D.sub.2-DTPA is produced after centrifugation
and freeze-drying.
[0039] IR (cm.sup.-1): 3438, 2939, 2678, 1725, 1634, 1228.
[0040] .sup.1H NMR (400 MHz, CDCl.sub.3): .delta. 1.04 (m), 1.18
(m), 3.07 (t, 16), 3.21 (t, 16), 3.58 (bs), 3.68 (m), 3.79 (d),
4.21 (bs).
Example 3
Preparation of Dendritic Compound P-D.sub.3-(DTPA)
[0041] a. Preparation of Chelate P-D.sub.3-(O.sub.2Bn)
[0042] The preparation process of the third generation
P-D.sub.3-(O.sub.2Bn) is similar to that of the first and second
generations. The product from step b. in example 2 (2.88 g, 0.40
mmol, 1 equiv), Benzylidene-2,2-bis(oxymethyl) propionic anhydride
(5.48 g, 12.8 mmol, 32 equiv), and DMAP (0.3151 g, 2.57 mmol, 6.4
equiv) are dissolved in 35 mL DCM at room temperature and reacted
for 24 hours. The extracting procedure in step a. of example 2 is
repeated, and the final product yield rate is about 89%. The
D.sub.n product is D.sub.3 with the structure of (III) as
follows.
##STR00004##
[0043] .sup.1H NMR (400 MHz, CDCl.sub.3): .delta. 0.89 (s, 24),
1.16 (s, 6), 1.17 (s, 12), 3.57 (t, 6), 3.67 (bs), 3.77 (t, 3),
4.15 (q, 6), 4.28 (t, 3), 4.33 (m, 16), 4.55 (d, 16), 5.37 (s, 8),
7.30 (m, 24), 7.35 (m, 16).
b. Preparation of Chelate P-D.sub.2-OH
[0044] The product (4 g) from step a. is dissolved in the mixture
of DCM and MeOH (1:1). Pd/C catalyst (0.4 g) is added, and stirred
for 24 hours under a hydrogen-saturated environment. White powder
product (1.8 g) is produced after filtering and freeze-drying.
[0045] .sup.1H NMR (400 MHz, CDCl.sub.3): .delta. 1.07 (s, 24),
1.27 (s, 6), 1.34 (s, 12), 3.47 (t), 3.64 (bs), 3.76 (m), 4.26 (m),
4.32 (dd, 10).
c. Synthesis of P-D.sub.3-DTPA.
[0046] The method of synthesizing the third generation
P-D.sub.3-DTPA is the same as aforementioned. P-D.sub.3-OH (1.097
g, 0.1938 mmol) and 1.814 g (3.6 mmol) DTPA-HSIE are mixed in a 50
mL round bottom conical vial and vacuum dried for 4 hours.
Anhydrous DMSO (10 mL) and 515 .mu.L Triethylamine are injected
into the mixture, and stirred for 64 hours at room temperature
under saturated nitrogen gas. After white precipitate is released
by means of acetonitrile/acetone solution, the white solid product,
P-D.sub.3-DTPA, is produced after centrifugation and
freeze-drying.
[0047] IR (cm.sup.-1): 3460, 2990, 2650, 1720, 1645, 1235.
[0048] .sup.1H NMR (400 MHz, CDCl.sub.3): .delta. 1.03 (s), 1.25
(s), 1.29 (s), 2.7 (m), 3.16 (t), 3.46 (t), 3.79 (bs), 3.80 (m),
3.97 (bs), 4.21 (m).
[0049] In the P-D.sub.n-DTPA dendritic compounds of the first,
second and third generation, the resonant frequency in NMR spectrum
of the methyl on hydrogen is decreased as the generation extends.
Therefore, it is proved that the dendritic compound of
P-D.sub.n-DTPA in the present example is the dendritic compound of
the first, second and third generations. In addition, infrared
spectrum can be applied to verify the structure of DTPA; in other
words, the original C--O bond of DTPA is disappeared at the peak of
1200 cm.sup.-1, and instead, the carbonyl peak is appeared between
signals of 1638 and 1598 cm.sup.-1. As a result, it is proved that
the dendritic compound in the present example possesses the DTPA to
chelate Gd.
Example 4
Preparation of the Final Complex P-D.sub.3-DTPA-Gd.sup.3+
[0050] P-D.sub.3-DTPA (0.066 g, 0.005 mmol) is dissolved in 10 mL
water, and a 16-time amount of GdCl.sub.3.6H.sub.2O (0.031 g, 0.08
mmol) is added. The pH value is adjusted in neutral (pH7) by 0.1 N
sodium hydroxide solution. The result of the reaction is verified
by FTIR and white solid product is produced after
freeze-drying.
[0051] IR (cm.sup.-1): 3426, 2919, 1615.
Characteristic Testing
[0052] By evaluating the effectiveness of the reacted dendritic
compound P-D.sub.3-DTPA-Gd.sup.3+ of the third generation as an
agent of enhancing image, it can be compared with the magnetizing
relaxation of DTPA-Gd (Magnevist.TM.) by directly comparing the
magnetizing relaxation rate via NMR. The results of comparison are
showed in Table 1 in which R.sub.1 and R.sub.2 respectively
represent vertical and horizontal relative relaxation times, and
B.sub.0 as the internal magnetic intensity of NMR. The greater
volumes of R.sub.1 and R.sub.2, the stronger image signal will be.
Therefore, Table 1 is clearly indicated the chelating Gd element of
third generation dendritic compound provides a superior imaging
result compared to DTPA-Gd (Magnevist.TM.), and demonstrated
distinct progress in NMR imaging.
TABLE-US-00001 TABLE 1 R.sub.1(20 MHz) R.sub.2 Compound B.sub.0 =
0.47 T B.sub.0 = 0.47 T Literature Magnevist .TM. 6.14 5.84 R.sub.1
= 3.4 R.sub.2 = 3.8 B.sub.0 = 1.0T PEG-G3-DTPA-Gd.sup.3+ 305 312.5
NIL
[0053] Furthermore, conventional imaging agents require high
concentration of Gd to achieve the ideal image, and it is also a
challenge to accumulate the imaging agent on a certain location.
The dendritic compound in this invention provides a vivid and clear
image with no need to accumulate the image agent on one position
and this situation promotes a more suitable clinical
application.
[0054] In addition, each dendritic compound in the present
invention contains protected OH functional groups, which extend to
a higher generation and possesses the magnifying ability by times.
Therefore, compared to known imaging agents, a better imaging
contrast is provided with the same amount. It is also known that
chelator with small molecule weight penetrates vascular endothelial
cells easily such that it disperses while circulating; the
dendritic compound is a high molecule carrier which decreases the
possibility of being drained away during blood circulation.
[0055] The "core" of the dendritic compound of the present
invention is polyethylene glycol and its derivatives. Polyethylene
glycol, a bio-compatible polymer certified by the FDA in the USA,
is usually applied to biomedical polymers and can be eliminated
spontaneously via circulation. Therefore, the dendritic compound of
the present invention can be an imaging agent with low
toxicity.
* * * * *