U.S. patent application number 16/141656 was filed with the patent office on 2019-03-28 for chemical modulators of store-operated calcium channels and their therapeutic applications.
This patent application is currently assigned to The Texas A&M University System. The applicant listed for this patent is The Texas A&M University System. Invention is credited to Lian He, Yubin Zhou.
Application Number | 20190092723 16/141656 |
Document ID | / |
Family ID | 65807148 |
Filed Date | 2019-03-28 |
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United States Patent
Application |
20190092723 |
Kind Code |
A1 |
Zhou; Yubin ; et
al. |
March 28, 2019 |
CHEMICAL MODULATORS OF STORE-OPERATED CALCIUM CHANNELS AND THEIR
THERAPEUTIC APPLICATIONS
Abstract
Methods of identification of inhibitors of calcium
release-activated calcium (CRAC) channel and small molecule
inhibitors of CRAC channel, including methods of their synthesis
and pharmaceutical use, are disclosed.
Inventors: |
Zhou; Yubin; (Houston,
TX) ; He; Lian; (Houston, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Texas A&M University System |
College Station |
TX |
US |
|
|
Assignee: |
The Texas A&M University
System
College Station
TX
|
Family ID: |
65807148 |
Appl. No.: |
16/141656 |
Filed: |
September 25, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62563511 |
Sep 26, 2017 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61P 35/00 20180101;
A61P 37/06 20180101; C07D 207/416 20130101 |
International
Class: |
C07D 207/416 20060101
C07D207/416; A61P 37/06 20060101 A61P037/06; A61P 35/00 20060101
A61P035/00 |
Goverment Interests
STATEMENT OF GOVERNMENT LICENSE RIGHTS
[0002] This invention was made with Government support under
Contract No. R01GM112003 awarded by the National Institutes of
Health. The Government has certain rights in the invention.
Claims
1. A method of treatment of a disease, disorder, or condition
treatable by inhibiting CRAC channel in a subject, comprising
administering to a subject in need thereof an amount of a CRAC
channel inhibitor effective to inhibit CRAC channel, wherein the
CRAC channel inhibitor is a compound of Formula I: ##STR00131## or
a pharmaceutically acceptable salt, solvate, or a hydrate thereof,
wherein X is an optionally substituted C6-C10 aryl or an optionally
substituted C5-C10 heteroaryl; Y is an optionally substituted C1-C8
alkyl, an optionally substituted C6-C10 aryl-C1-C8 alkyl, an
optionally substituted C5-C10 heteroaryl-C1-C8 alkyl, an optionally
substituted C3-C10 heteroalkyl, an optionally substituted C3-C6
heterocyclyl, an optionally substituted C6-C10 aryl, or an
optionally substituted C5-C10 heteroaryl; and Z is an optionally
substituted C6-C10 aryl or an optionally substituted C5-C10
heteroaryl.
2. The method of claim 1, wherein X is an optionally substituted
phenyl.
3. The method of claim 1, wherein X is a phenyl substituted with
one, two, or three groups selected from C1-C6 alkyl, carboxyl,
alkoxycarbonyl, and amido group.
4. The method of claim 1, wherein the compound has the structure of
Formula II: ##STR00132## wherein R.sup.1 is H, an optionally
substituted C1-C6 alkyl, COOH, COOR.sup.2, CONH.sub.2, or
CONHR.sup.2; R.sup.2 is an optionally substituted C1-C6 alkyl; Y is
an optionally substituted C1-C8 alkyl, an optionally substituted
C6-C10 aryl-C1-C8 alkyl, or an optionally substituted C5-C10
heteroaryl-C1-C8 alkyl; and Z is an optionally substituted C6-C10
aryl or an optionally substituted C5-C10 heteroaryl.
5. The method of claim 1, wherein Y is an optionally substituted
phenethyl.
6. The method of claim 1, wherein the compound has the structure of
Formula III: ##STR00133## wherein R1 is H, COOH, COOR.sup.2, or
CONHR.sup.2; R.sup.2 is an optionally substituted C1-C6 alkyl;
R.sup.4 is H or an optionally substituted C1-C6 alkyl; R.sup.5 is H
or an optionally substituted C1-C6 alkyl; and Z is an optionally
substituted C6-C10 aryl or an optionally substituted C5-C10
heteroaryl.
7. The method of claim 1, wherein Y is methyl, ethyl, propyl,
n-butyl, tert-butyl, cyclopropyl, phenyl, benzyl, 4-methoxybenzyl,
3,4-dimethoxyphenyl, 4-sulfonamidophenethyl, or
5-methylbenzo[d][1,3]dioxolyl.
8. The method of claim 1, wherein Z is phenyl, 4-halophenyl,
3-trifluoromethyl-phenyl, 2,5-dichlorophenyl,
3-chloro-4-methyl-phenyl, 2-methoxy-phenyl,
4-methoxycarbonyl-phenyl, benzo[d][1,3]dioxolyl,
3,5-dichlorophenyl, 3-methoxyphenyl, or 3-halophenyl.
9. The method of claim 1, wherein the compound is: ##STR00134##
##STR00135## ##STR00136## ##STR00137##
10. The method of claim 1, wherein the condition is an immune
system disease, a hyperplastic disease, or cancer.
11. The method of claim 1, wherein the condition is colon cancer,
breast cancer, leukemia, or glioma.
12. The method of claim 1, wherein the condition is an organ or a
tissue transplant rejection.
13. A compound represented by Formula II: ##STR00138## or a
pharmaceutically acceptable salt, solvate, or a hydrate thereof,
wherein R.sup.1 is selected from H, C1-C6 alkyl, COOH, COOR.sup.2,
or CONHR.sup.2, and R.sup.2 is an optionally substituted C1-C6
alkyl; Y is an optionally substituted C1-C8 alkyl, an optionally
substituted C6-C10 aryl-C1-C8 alkyl, or an optionally substituted
C5-C10 heteroaryl-C1-C8 alkyl; and Z is an optionally substituted
C6-C10 aryl or an optionally substituted C5-C10 heteroaryl.
14. The compound of claim 13, wherein Y is an optionally
substituted phenethyl.
15. The compound of claim 13, wherein Y is
4-sulfonamidophenethyl.
16. The compound of claim 13, wherein the compound has the
structure of Formula III: ##STR00139## wherein R.sup.1 is H, an
optionally substituted C1-C6 alkyl, COOH, COOR.sup.2, CONH.sub.2,
or CONHR.sup.2; R.sup.2 is an optionally substituted C1-C6 alkyl;
R.sup.4 is H or an optionally substituted C1-C6 alkyl; R.sup.5 is H
or an optionally substituted C1-C6 alkyl; and Z is an optionally
substituted C6-C10 aryl or an optionally substituted C5-C10
heteroaryl.
17. The compound of claim 13, wherein Y is methyl, ethyl, propyl,
n-butyl, tert-butyl, cyclopropyl, phenyl, benzyl, 4-methoxybenzyl,
3,4-dimethoxyphenyl, 4-sulfonamidophenethyl, or
5-methylbenzo[d][1,3]dioxolyl.
18. The compound of claim 13, wherein Z is phenyl, 4-halophenyl,
3-trifluoromethyl-phenyl, 2,5-dichlorophenyl,
3-chloro-4-methyl-phenyl, 2-methoxy-phenyl,
4-methoxycarbonyl-phenyl, benzo[d][1,3]dioxolyl,
3,5-dichlorophenyl, 3-methoxyphenyl, or 3-halophenyl.
19. The compound of claim 13, wherein the compound is: ##STR00140##
##STR00141##
20. A pharmaceutical composition comprising the compound of claim
13 and a pharmaceutically acceptable carrier.
Description
CROSS-REFERENCES TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Patent
Application No. 62/563,511, filed Sep. 26, 2017, the disclosure of
which is incorporated herein by reference in its entirety.
STATEMENT REGARDING SEQUENCE LISTING
[0003] The sequence listing associated with this application is
provided in text format in lieu of a paper copy and is hereby
incorporated by reference into the specification. The name of the
text file containing the sequence listing is
TAMUS167344_SEQ_final_2018-09-20.txt. The text file is 2.88 KB; was
created on Sep. 20, 2018; and is being submitted via EFS-Web with
the filing of the specification.
BACKGROUND OF THE INVENTION
[0004] In cells, calcium (Ca.sup.2+) is an important secondary
messenger, and the increase of calcium in cytoplasm is involved in
various signaling pathways, further mediating a series of
fundamental biological processes, such as contraction of skeletal
muscles, release of neurotransmitters, metabolism of mitochondria,
gene transcription, cell proliferation, differentiation, and
apoptosis. Under normal physiological conditions, cells are exposed
to high levels of calcium, and the extracellular concentration of
calcium is about 1-2 mM. However, in the cytoplasm, the
intracellular calcium concentration is 1,000-10,000 times lower,
about 10.sup.-6-10.sup.-7 M. Additionally, in the intracellular
calcium stores, mainly endoplasmic reticulum and sarcoplasmic
reticulum, calcium concentration is about 10.sup.-5 M. This calcium
gradient constitutes the foundation of calcium serving as a
secondary messenger. Aberrant Ca.sup.2+ signaling is implicated in
tumorigenesis and the pathogenesis of immunodeficiency, allergy,
and autoimmune and inflammatory disorders. Targeting Ca.sup.2+
signaling pathway may hold therapeutic potential in the treatment
of hematological malignancies and other solid cancers
[0005] Calcium signal is well controlled through various types of
calcium channels in the cell membrane. In excitable cells, such as
skeletal muscle and neuronal cells, calcium level is mainly
regulated by voltage-gated calcium channels. However, in
non-excitable cells, such as lymphocytes and most cancer cells,
store-operated calcium (SOC) channel is the major calcium entry
pathway from the extracellular space, in which depletion of calcium
in intracellular stores can induce calcium influx through cell
membrane. To date, several distinct store-operated channels have
been reported, with the calcium release-activated calcium (CRAC)
channel being the most well-characterized among them.
[0006] CRAC channel was first discovered in immune cells, where its
function is well studied. Its two key components, the regulatory
protein, STIM1 (the stromal interaction molecule 1) and the
pore-forming subunit, Orai1 (also known as CRACM1) constitute the
molecular basis of the CRAC current. STIM1, a single-transmembrane
protein located in endoplasmic reticulum (ER) membrane, can sense
the calcium concentration changes in ER. Orai1 has four
transmembrane domains and exits as a multimer. After activation by
STIM1, Orai1 forms a functional oligomer (most probably as a
hexamer) to allow the calcium to pass through the channel. When
antigens bind to T-cell and B-cell receptors or when
antigen-antibody complex binds to Fc receptors on mast cells,
natural killer cells, macrophages, and dendritic cells,
phospholipase C (PLC) is activated and in turn hydrolyzes the
phosphatidylinositol 4,5 bisphosphate PIP.sub.2 to generate
inositol-1,4,5-trisphosphate (IP3), which binds to the ER-resident
IP3 receptor and triggers the release of Ca.sup.2+ from the ER
lumen into cytoplasm. The decrease of free Ca.sup.2+ in ER stores
is sensed by STIM1 via its ER-luminal EF-SAM domain that contains a
Ca.sup.2+-binding EF-hand motif. Then, STIM1 forms oligomers and
migrates toward ER-PM junctions (puncta), where it engages the
ORAI1 Ca.sup.2+ channels and evokes Ca.sup.2+ influx. Finally, the
resultant sustained elevation of cytosolic Ca.sup.2+ level
activates the Ca.sup.2+/calmodulin-dependent phosphatase
calcineurin and transcription factors, including nuclear factor of
activated T cells (NFAT), which translocates from the cytoplasm to
the nucleus and thereby regulates gene transcription during
lymphocyte activation and differentiation. In addition to immune
cells, CRAC channel is widely distributed in other various types of
cells and tissues, including brain, lung, liver, kidney, spleen,
thymus, lymph nodes, skeletal muscle, heart, bone, teeth, etc. Any
effectors, such as ligand binding to some GPCRs receptors and
tyrosine kinases receptors, that can stimulate the IP3 generation
can also induce store-operated calcium current and further mediate
the downstream signal pathway and regulated gene transcription.
[0007] Although both ORAI and STIM are widely expressed in
different tissues, the clinical consequences of dysfunction of CRAC
channel are primarily limited to the immune system. Thus, drug
candidates that specifically target CRAC channels have a great
potential to selectively suppress abnormal immune function and/or
reduce the side effects of the existing immunosuppressant drugs,
such as cyclosporin and tacrolimus. Additionally, abnormal CRAC
channel activity, mainly due to augmented SOCE which resulted in
cell calcium overload, was linked with other human diseases, such
as myopathy, occlusive vascular diseases, cardiac hypertrophy,
pancreatitis, and endothelial dysfunction. The role of CRAC channel
in progression of cancers, such as in cancer cell growth,
migration, invasion, and metastasis, is beginning to receive more
attention. Dysregulated Ca.sup.2+ influx due to augmented STIM-ORAI
signaling has been observed in many types of tumor cells, including
breast, prostate, liver, lung, colon, skeletal muscle, cervical,
nasopharyngeal, epidermoid, and glioma cancer cells, thereby making
CRAC channel an attractive target for drug development.
[0008] A number of CRAC channel inhibitors have been developed,
such as SKF-96365, 2-APB, BTP. However, presently, there are no
viable clinical candidates because of the low selectivity and/or
low activity exhibited by these compounds. Therefore, there is
still an urgent need and high interest in developing novel CRAC
channel inhibitors having high selectivity and potency.
SUMMARY OF THE INVENTION
[0009] In one aspect, provided herein is a CRAC channel inhibitor
represented by Formula I:
##STR00001##
[0010] or a pharmaceutically acceptable salt, solvate, or a hydrate
thereof, wherein:
[0011] X is an optionally substituted C6-C10 aryl or an optionally
substituted C5-C10 heteroaryl;
[0012] Y is an optionally substituted C1-C8 alkyl, an optionally
substituted C6-C10 aryl-C1-C8 alkyl, an optionally substituted
C5-C10 heteroaryl-C1-C8 alkyl, an optionally substituted C3-C10
heteroalkyl, an optionally substituted C3-C6 heterocyclyl, an
optionally substituted C6-C10 aryl, or an optionally substituted
C5-C10 heteroaryl; and
[0013] Z is an optionally substituted C6-C10 aryl or an optionally
substituted C5-C10 heteroaryl.
[0014] In some embodiments of Formula I, X is an optionally
substituted phenyl. In some embodiments, X is a phenyl substituted
with one, two, or three groups selected from C1-C6 alkyl, carboxyl,
alkoxycarbonyl, and amido group.
[0015] In some embodiments, the CRAC channel inhibitor has the
structure of Formula II:
##STR00002##
[0016] wherein
[0017] R.sup.1 is H, an optionally substituted C1-C6 alkyl, COOH,
COOR.sup.2, CONH.sub.2, or CONHR.sup.2;
[0018] R.sup.2 is an optionally substituted C1-C6 alkyl;
[0019] Y is an optionally substituted C1-C8 alkyl, an optionally
substituted C6-C10 aryl-C1-C8 alkyl, or an optionally substituted
C5-C10 heteroaryl-C1-C8 alkyl; and
[0020] Z is an optionally substituted C6-C10 aryl or an optionally
substituted C5-C10 heteroaryl.
[0021] In some embodiments of Formulae I or II, Y is an optionally
substituted phenethyl.
[0022] In some embodiments of Formulae I or II, the CRAC channel
inhibitor has the structure of Formula III:
##STR00003##
[0023] wherein
[0024] R.sup.1 is H, an optionally substituted C1-C6 alkyl, COOH,
COOR.sup.2, CONH.sub.2, or CONHR.sup.2;
[0025] R.sup.2 is an optionally substituted C1-C6 alkyl;
[0026] R.sup.4 is H or an optionally substituted C1-C6 alkyl;
[0027] R.sup.5 is H or an optionally substituted C1-C6 alkyl;
and
[0028] Z is an optionally substituted C6-C10 aryl or an optionally
substituted C5-C10 heteroaryl.
[0029] In some embodiments of Formulae I or II, Y is methyl, ethyl,
propyl, n-butyl, tert-butyl, cyclopropyl, phenyl, benzyl,
4-methoxybenzyl, 3,4-dimethoxyphenyl, 4-sulfonamidophenethyl, or
5-methylbenzo[d][1,3]dioxolyl.
[0030] In some embodiments of Formulae I, II, or III, Z is phenyl,
4-halophenyl, 3-trifluoromethyl-phenyl, 2,5-dichlorophenyl,
3-chloro-4-methyl-phenyl, 2-methoxy-phenyl,
4-methoxycarbonyl-phenyl, benzo[d][1,3]dioxolyl,
3,5-dichlorophenyl, 3-methoxyphenyl, or 3-halophenyl.
[0031] In another aspect, provided herein is a method of treatment
of a disease, disorder, or condition treatable by inhibiting CRAC
channel in a subject, comprising administering to the subject in
need thereof an amount of a CRAC channel inhibitor effective to
inhibit CRAC channel, wherein the CRAC channel inhibitor is a
compound of any one of Formulae I, II, or III.
[0032] In some embodiments, the condition treatable by inhibition
of CRAC channel activity is an immune system disease, a
hyperplastic disease, or cancer. In some embodiments, the condition
is colon cancer, breast cancer, leukemia, or glioma. In some
embodiments, the condition is an organ or a tissue transplant
rejection.
[0033] In yet another aspect, provided herein is a pharmaceutical
composition comprising a CRAC channel inhibitor represented by
Formulae I, II, or III and a pharmaceutically acceptable carrier.
In some embodiments, the composition further comprises one or more
inactive components such as solvents, excipients, stabilizing
agents, or diluents.
[0034] In yet another aspect, provided herein is a method of
identifying an inhibitor of CRAC channel, the method
comprising:
[0035] (a) generating on a computer a three-dimensional structure
of human Orai1 protein of SEQ ID NO:1 by aligning the sequence of
human Orai1 protein with the sequence of Orai1 protein from
Drosophila melanogaster to generate a homology model of human
Orai1;
[0036] (b) employing said three-dimensional model from step (a) to
identify a potential inhibitor of CRAC;
[0037] (c) obtaining said potential inhibitor; and
[0038] (d) contacting said potential inhibitor with CRAC to
determine the ability of said potential inhibitor to inhibit CRAC
activity, whereby inhibition of CRAC activity identifies said
inhibitor.
[0039] In some embodiments, the potential inhibitor forms
hydrophobic or .pi.-.pi. interactions with Trp 377 and Trp 678
amino acids of SEQ ID NO:1 and salt bridge interactions with Arg
384 and Arg 986 amino acids of SEQ ID NO:1.
[0040] In some embodiments, the contacting of a potential inhibitor
of CRAC with CRAC is an in vitro assay. In some embodiments, the in
vitro assay is GFP-NFAT translocation assay.
[0041] In yet another aspect, provided herein is a method of
preparing a compound of Formula I, wherein the method
comprises:
[0042] (a) contacting a thiourea compound of Formula IV:
##STR00004##
[0043] with a compound of Formula V:
##STR00005##
in a suitable solvent thereby forming the compound of Formula
I.
DESCRIPTION OF THE DRAWINGS
[0044] The foregoing aspects and many of the attendant advantages
of this invention will become more readily appreciated as the same
become better understood by reference to the following detailed
description, when taken in conjunction with the accompanying
drawings.
[0045] FIGS. 1A and 1B demonstrate the homology model of CRAC
channel: top view (2A) and side view (2B).
[0046] FIG. 2 depicts the docking conformations (grey lines) of the
compounds in the binding site of the CRAC homology model.
[0047] FIG. 3 summarizes the primary activity (NFAT
nucleus-to-cytosol ratio) of Compounds 1-51 from the virtual
screening.
[0048] FIG. 4 compares IC.sub.50 curves of representative Compounds
3, 15, 21, and 41 from the virtual screening.
[0049] FIG. 5 demonstrates the inhibitory activity of Compound 41,
a representative compound, on calcium influx.
[0050] FIG. 6 shows the proposed interactions of Compound 4, a
representative compound, with CRAC channel.
[0051] FIG. 7 shows the structure of reported CRAC channel
inhibitors that were used as the template to establish the
pharmacophores used in the generation of the chemical structures of
the compounds of the invention.
[0052] FIG. 8 is the schematic of the pharmacophore model of CRAC
inhibitors showing Compound 41, a representative compound, bound to
the CRAC channel.
[0053] FIGS. 9A-9F demonstrate that representative Compounds 87
(FIGS. 9A, 9C, and 9E) and 53 (FIGS. 9B, 9D, and 9F) significantly
inhibit cytokine IL-2 expression in primary T cells, with the
calculated IC.sub.50 of 0.86.+-.0.12 .mu.M and 15.6.+-.1.17 .mu.M,
respectively.
[0054] FIG. 10 shows that Compound 53 inhibits cytokine expression
in Jurkat cells.
[0055] FIGS. 11A and 11B demonstrate the effect of Compound 87 on
cell cycle in Jurkat cells: control (11A), Compound 87 (11B).
[0056] FIGS. 12A and 12B demonstrate the effect of Compound 87 on
cell cycle in U87 cells: control (12A), Compound 87 (12B).
[0057] FIGS. 13A-13C show the inhibitory activity of representative
Compounds 87, 53, 65, and 66 on the cell migration and invasion of
MDA-MB-231 breast cancer cells: wound healing assay (13A),
migration (13B), and invasion assay (13C).
[0058] FIGS. 14A and 14B demonstrate that Compound 53 has antitumor
activity in the azoxymethane (AOM)-induced mouse colon cancer model
by reducing the number of tumors formed compared to untreated
control group and group treated with a known anti-cancer agent
CsA.
DETAILED DESCRIPTION OF THE INVENTION
[0059] While the invention will be described in conjunction with
the enumerated claims, it will be understood that they are not
intended to limit the invention to those claims. On the contrary,
the invention is intended to cover all alternatives, modifications,
and equivalents, which may be included within the scope of the
present invention as defined by the claims.
Definitions
[0060] As used herein, the term "alkyl" includes straight-chain,
branched-chain, and cyclic monovalent hydrocarbyl radicals, and
combinations thereof, which contain only C and H when they are
unsubstituted. Examples include methyl, ethyl, isobutyl,
cyclohexyl, cyclopentylethyl, 2-propenyl, 3-butynyl, and the like.
The total number of carbon atoms in each such group is sometimes
described herein, e.g., when the group can contain up to ten carbon
atoms, it can be represented as 1-10C, C1-C10, C.sub.1-C.sub.10,
C.sub.1-10, or C1-10. The term "heteroalkyl," as used herein, means
the corresponding hydrocarbon wherein one or more chain carbon
atoms have been replaced by a heteroatom. Exemplary heteroatoms
include N, O, S, and P. When heteroatoms are allowed to replace
carbon atoms, for example, in heteroalkyl groups, the numbers
describing the group, though still written as e.g. C3-C10,
represent the sum of the number of carbon atoms in the cycle or
chain plus the number of such heteroatoms that are included as
replacements for carbon atoms in the cycle or chain being
described.
[0061] Alkyl groups can be optionally substituted to the extent
that such substitution makes sense chemically. Typical substituents
include, but are not limited to, halogens (F, Cl, Br, I), .dbd.O,
.dbd.NCN, .dbd.NOR, .dbd.NR, OR, NR.sub.2, SR, SO.sub.2R,
SO.sub.2NR.sub.2, NRSO.sub.2R, NRCONR.sub.2, NRC(O)OR, NRC(O)R, CN,
C(O)OR, C(O)NR.sub.2, OC(O)R, C(O)R, and NO.sub.2, wherein each R
is independently H, C1-C8 alkyl, C2-C8 heteroalkyl, C1-C8 acyl,
C2-C8 heteroacyl, C6-C10 aryl, or C5-C10 heteroaryl, and each R is
optionally substituted with halogens (F, Cl, Br, I), .dbd.O,
.dbd.NCN, .dbd.NOR', .dbd.NR', OR', NR'.sub.2, SR', SO.sub.2R',
SO.sub.2NR'.sub.2, NR'SO.sub.2R', NR'CONR'.sub.2, NR'C(O)OR',
NR'C(O)R', CN, C(O)OR', C(O)NR'.sub.2, OC(O)R', C(O)R', and
NO.sub.2, wherein each R' is independently H, C1-C8 alkyl, C2-C8
heteroalkyl, C1-C8 acyl, C2-C8 heteroacyl, C6-C10 aryl or C5-C10
heteroaryl. Alkyl groups can also be substituted by C1-C8 acyl,
C2-C8 heteroacyl, C6-C10 aryl, or C5-C10 heteroaryl, each of which
can be substituted by the substituents that are appropriate for the
particular group.
[0062] "Aromatic" or "aryl" substituent or moiety refers to a
monocyclic or fused bicyclic moiety having the well-known
characteristics of aromaticity; examples of aryls include phenyl
and naphthyl. Similarly, "heteroaromatic" and "heteroaryl" refer to
such monocyclic or fused bicyclic ring systems which contain as
ring members one or more heteroatoms. Suitable heteroatoms include
N, O, and S, inclusion of which permits aromaticity in 5-membered
rings as well as 6-membered rings. Typical heteroaromatic systems
include monocyclic C5-C6 aromatic groups such as pyridyl,
pyrimidyl, pyrazinyl, thienyl, furanyl, pyrrolyl, pyrazolyl,
thiazolyl, oxazolyl, and imidazolyl, and fused bicyclic moieties
formed by fusing one of these monocyclic groups with a phenyl ring
or with any of the heteroaromatic monocyclic groups to form a
C8-C10 bicyclic group such as indolyl, benzimidazolyl, indazolyl,
benzotriazolyl, isoquinolyl, quinolyl, benzothiazolyl,
benzofuranyl, pyrazolopyridyl, quinazolinyl, quinoxalinyl,
cinnolinyl, and the like. Any monocyclic or fused ring bicyclic
system which has the characteristics of aromaticity in terms of
electron distribution throughout the ring system is included in
this definition. It also includes bicyclic groups where at least
the ring which is directly attached to the remainder of the
molecule has the characteristics of aromaticity. Typically, the
ring systems contain 5-14 ring member atoms. Typically, monocyclic
heteroaryls contain 5-6 ring members, and bicyclic heteroaryls
contain 8-10 ring members. When heteroatoms are allowed to replace
carbon atoms in heteroaryl groups, the numbers describing the
group, though still written as, e.g. C5-C10, represent the sum of
the number of carbon atoms in the cycle plus the number of such
heteroatoms that are included as replacements for carbon atoms in
the cycle being described. For example, a pyridyl group can be
referred to as a C6 heteroaryl.
[0063] Aryl and heteroaryl moieties can be substituted with a
variety of substituents including C1-C8 alkyl, C5-C12 aryl, C1-C8
acyl, and heteroforms of these, each of which can itself be further
substituted; other substituents for aryl and heteroaryl moieties
include halogens (F, Cl, Br, I), OR, NR.sub.2, SR, SO.sub.2R,
SO.sub.2NR.sub.2, NRSO.sub.2R, NRCONR.sub.2, NRC(O)OR, NRC(O)R, CN,
C(O)OR, C(O)NR.sub.2, OC(O)R, C(O)R, and NO.sub.2, wherein each R
is independently H, C1-C8 alkyl, C2-C8 heteroalkyl, C6-C10 aryl,
C5-C10 heteroaryl, C6-C10 aryl-C1-C5 alkyl, or C5-C10
heteroaryl-C1-C5 alkyl, and each R is optionally substituted as
described above for alkyl groups. The substituent groups on an aryl
or heteroaryl group can be further substituted with the groups
described herein as suitable for each type of such substituents or
for each component of the substituent. Thus, for example, an
arylalkyl substituent can be substituted on the aryl portion with
substituents described herein as typical for aryl groups, and it
can be further substituted on the alkyl portion with substituents
described herein as typical or suitable for alkyl groups.
[0064] As used herein, the term "arylalkyl" refers to an alkyl
substituted with an aryl. Arylalkyls are represented by the number
of carbon atoms in each alkyl and aryl; for example, a C6 aryl-C2
alkyl refers to a C2 alkyl substituted with a C6 aryl. Non-limiting
examples of arylalkyls are benzyl (a C6 aryl-C1 alkyl) and
phenethyl (a C6 aryl-C2 alkyl). Similarly, the term
"heteroarylalkyl" refers to an alkyl substituted with a heteroaryl.
Heteroarylalkyls are represented by the number of carbon atoms in
each alkyl and heteroaryl; for example, a C6 heteroaryl-C2 alkyl
refers to a C2 alkyl, e.g., ethyl, substituted with a C6
heteroaryl, e.g., pyridyl.
[0065] "Optionally substituted," as used herein, indicates that the
particular group being described can have one or more hydrogen
substituents replaced by a non-hydrogen substituent. In some
optionally substituted groups or moieties, all hydrogen
substituents are replaced by a non-hydrogen substituent (e.g., a
polyfluorinated alkyl such as trifluoromethyl). If not otherwise
specified, the total number of such substituents that can be
present is equal to the number of H atoms present on the
unsubstituted form of the group being described. Where an optional
substituent is attached via a double bond, such as a carbonyl
oxygen or oxo (.dbd.O), the group takes up two available valences,
so the total number of substituents that may be included is reduced
according to the number of available valences.
[0066] As used herein, the term "immune system diseases" refers to
a series of disorders of the immune system, including
immunodeficiency disorders, overactive immune response (allergy),
and autoimmune disorders (e.g., disorders in which the immune
system attacks normal and healthy tissues). The immune diseases
that can be treated with the compounds of the invention are
preferably the conditions induced by the overactive or abnormal
immune recognition.
[0067] A "therapeutically effective amount" refers to an amount
effective, at dosages and for periods of time necessary, to achieve
the desired therapeutic result, for example, reduced levels of CRAC
channel activity. A therapeutically effective amount of a compound
can vary according to factors such as the disease state, age, sex,
and weight of the subject, and the ability of the compound to
elicit a desired response in the subject. An individual
therapeutically effective amount can be determined according to the
methods known in the art. Dosage regimens can be adjusted to
provide the optimum therapeutic response. A therapeutically
effective amount is also one in which any toxic or detrimental
effects of the compound are outweighed by the therapeutically
beneficial effects. A "prophylactically effective amount" refers to
an amount effective, at dosages and for periods of time necessary,
to achieve the desired prophylactic result, such as inhibition of
CRAC channel.
[0068] As used herein, the term "treat", "treating", and
"treatment" refer to administering a compound of the invention or a
pharmaceutical composition comprising a compound of the invention
to a patient thereby generating a therapeutic effect, such as
eliminating or alleviating one or more existing symptoms of a
disease, preventing any additional symptoms, and/or preventing
further progression of the disease. As used herein, the term
"disease, disorder, or condition treatable by inhibiting CRAC
channel" refers to a disease, disorder, or condition in which CRAC
channel is involved in the pathway related to for the disease,
disorder, or condition, and that inhibiting CRAC channel results in
the treatment or prevention of the disease, disorder, or
condition.
[0069] As used herein, the term "transplantation" refers to removal
of organs, bone marrow, stem cell, or other tissues from one
subject and insertion into another subject. After transplantation,
the functionality and viability of the transplanted organs, bone
marrow, stem cell, and/or tissues in the new host can be maintained
through the use of an immunosuppressant.
Compound Virtual Screening
[0070] Compared with the classical drug discovery methods,
computer-aided drug discovery is a convenient and low-cost way to
find a lead compound with a novel chemical scaffold. To date, few
literature reports describing the use of this method to discover
CRAC channel inhibitors have been published. In this invention,
based on the crystal structure of Orai1 from Drosophila
melanogaster, the inventors have built a virtual screening method
to discover novel CRAC channel inhibitors. Specifically, first the
human Orai1 amino acid sequence was obtained from Uniprot database
(Uniprot ID: Q96D31). Then, the alignment of the amino acid
sequence between human Orai1 protein and Drosophila melanogaster
Orai1 protein was conducted using the Cobalt method. Then,
according to the alignment results, Modeler 9.11 software was used
to generate the homology model of human Orai1. Then, the rough
model was solvated by using the TIP3P water model, subjected to
500-steps of molecular mechanics minimization and molecular
dynamics simulations at 300 K for 1.0 ns using the SANDER module in
AMBER 8 program to obtain a refined model, as shown in FIG. 2.
Then, using this CRAC homology model and DOCK 6 software, a virtual
screening of the SPECS database containing about 300,000 compounds
was conducted. About 51 compounds were identified for biological
evaluation. The structures of the compounds are shown in Table 1,
and the docking results are shown in FIG. 3.
TABLE-US-00001 TABLE 1 Structures of some representative hits from
the virtual screening experiments Compound Number Structure of the
compounds IC.sub.50 Value 01 ##STR00006## >200 02 ##STR00007##
>200 03 ##STR00008## 143.7 04 ##STR00009## >200 05
##STR00010## >200 06 ##STR00011## >200 07 ##STR00012##
>200 08 ##STR00013## >200 09 ##STR00014## >200 10
##STR00015## >200 11 ##STR00016## >200 12 ##STR00017##
>200 13 ##STR00018## >200 14 ##STR00019## >200 15
##STR00020## 173.6 16 ##STR00021## >200 17 ##STR00022## >200
18 ##STR00023## >200 19 ##STR00024## >200 20 ##STR00025##
>200 21 ##STR00026## 60.3 (agonist) 22 ##STR00027## >200 23
##STR00028## >200 24 ##STR00029## >200 25 ##STR00030##
>200 26 ##STR00031## >200 27 ##STR00032## >200 28
##STR00033## >200 29 ##STR00034## >200 30 ##STR00035##
>200 31 ##STR00036## >200 32 ##STR00037## >200 33
##STR00038## >200 34 ##STR00039## >200 35 ##STR00040##
>200 36 ##STR00041## >200 37 ##STR00042## >200 38
##STR00043## >200 39 ##STR00044## >200 40 ##STR00045##
>200 41 ##STR00046## 278.83 42 ##STR00047## >200 43
##STR00048## >200 44 ##STR00049## >200 45 ##STR00050##
>200 46 ##STR00051## >200 47 ##STR00052## >200 48
##STR00053## >200 49 ##STR00054## >200 50 ##STR00055##
>200 51 ##STR00056## >200
Inhibitory Activity Assay on CRAC Channel
[0071] It is known that thapsigargin (TG) can induce the CRAC
channel to open resulting in the calcium influx. The elevation of
calcium in cytoplasm can activate the Ca.sup.2+-calcineurin-NFAT
pathway followed by NFAT translocation from the cytoplasm to the
nucleus to regulate gene transcription. Therefore, the inventors
built a GFP-NFAT translocation-based high-content screening method
to evaluate the activity of compounds on CRAC channel. Briefly, a
HeLa cell line stably expressing GFP-NFAT was established and used,
and the images after chemical stimulation in the presence of TG
were acquired using an IN Cell Analyzer 6000 confocal laser imaging
system, and then the GFP fluorescent intensity ratio between
cytoplasm and nucleus was analyzed to reflect the inhibitory
activity of compound on CRAC channel.
[0072] Briefly, GFP-NFAT stable cells were cultured in Dulbecco's
modified eagle's medium (DMEM) supplemented with 10% FBS in 5%
carbon dioxide at 37.degree. C. When it reached 90% confluency, a
cell suspension with a concentration of 8000/mL was prepared, and
an amount of 2000 cells per well (25 .mu.L/well) was seeded in 384
well plate, putting it at the room temperature for 1 h to make sure
the cells distribute evenly, then the cells were incubated
overnight. First, primary screening of the selected compounds was
conducted. A series of compound solutions with a concentration of
200 .mu.M in MEDM medium were prepared in a 96 well plate and then
added to a 384 well plate using a Beckman Coulter automatic drug
adding system, in 4 duplicates, and incubated for 30 min at
37.degree. C. SKF was selected as the positive control. Then, 1
.mu.M TG and 1 mM Ca.sup.2+ were added to 384-well plate using
Beckman Coulter automatic drug adding system and incubated for 20
min. Subsequently, 384 well plate was gently washed with PBS twice,
and the cells were fixed with 4% PFA (25 .mu.l per well) for
10.about.15 mins at room temperature, then washed with PBS gently,
added 0.5% Triton X-100 (25 .mu.L per well), and incubated for 5
mins aFt room temperature, stained with DAPI (1 .mu.g/mL) for
5.about.10 mins at room temperature, washed with PBS and added 30
.mu.L PBS per well to image on confocal laser imaging system
(objective lens: 10.times., FITC and UV). Using Pipeline Plot
software (NAFT translocation protocol), the intensity of green
fluorescence was analyzed in nucleus and cytosol, calculate the
ratio of nucleus: cytosol, normalize TG stimulate NFAT
translocation as 1 and no TG adding as 0. Finally, the data was
analyzed using GraphPad Prism 5 software. The compounds which
showed activity on CRAC channel were further evaluated and the
IC.sub.50 value was calculated using the same method described
above.
[0073] The inhibitor activity on CRAC of these 51 compounds
screened out from the small molecule library were evaluated using
the method describe above. The result showed that Compounds 03, 15,
and 41 demonstrated good activity (FIG. 3). Then, the IC.sub.50 of
these three compounds were calculated, and as shown in FIG. 4, the
IC.sub.50 value was about 100 .mu.M. It was noted that compounds
Compound 03 and Compound 41 have a similar chemical structure that
contain a general substructure. Therefore, the compounds with the
similar chemical structure may have inhibitory activity on calcium
influx CRAC channel. In addition, Compound 41 also showed obvious
inhibitory activity on calcium influx, as illustrated in FIG. 5.
Therefore, the Compound 41 was selected as the lead compound to
optimize the structure so as to improve the activity.
[0074] Optimization of Compound 41
[0075] In order to understand the interaction between Compound 41
and CRAC channel, the structure of Compound 41 was re-docked into
the active site, and the interactions were optimized by molecular
mechanics and molecular dynamics. After refinements, it was found
that the interaction between Compound 41 and CRAC channel seems to
be mainly dependent on strong hydrophobic and/or .pi.-.pi.
interactions with Trp 377 and Trp 678, as well as salt bridge
interactions with Arg 384 and Arg 986 (as shown in FIG. 7).
[0076] In addition, in order to aid the lead compound optimization,
a working pharmacophore model was developed based on the structure
of reported CRAC channel inhibitors, which are shown in FIG. 7,
using the Hipop algorithm implemented in the Discovery Studio
package. Briefly, the initial working pharmacophore model built
consisted of three common features as critical fragments for
activities: one hydrogen binding acceptor and two hydrophobic
groups (as shown in FIG. 8). Such results are consistent with the
homology model as well. This model in conjunction with the
interaction model was used to guide the optimization of the lead
compounds.
[0077] Thus, in an aspect, provided herein is a method of
identifying an inhibitor of CRAC channel, the method
comprising:
[0078] (a) generating on a computer a three-dimensional structure
of human Orai1 protein of SEQ ID NO:1 by aligning the sequence of
human Orai1 protein with the sequence of Orai1 protein from
Drosophila melanogaster to generate a homology model of human
Orai1;
[0079] (b) employing said three-dimensional model from step (a) to
identify a potential inhibitor of CRAC;
[0080] (c) obtaining said potential inhibitor; and
[0081] (d) contacting said potential inhibitor with CRAC to
determine the ability of said potential inhibitor to inhibit CRAC
activity, whereby inhibition of CRAC activity identifies said
inhibitor.
[0082] In some embodiments, the potential inhibitor forms
hydrophobic or .pi.-.pi. interactions with Trp 377 and Trp 678
amino acids of SEQ ID NO:1 and salt bridge interactions with Arg
384 and Arg 986 amino acids of SEQ ID NO:1.
[0083] In some embodiments, the contacting of a potential inhibitor
of CRAC with CRAC is an in vitro assay. In some embodiments, the in
vitro assay is GFP-NFAT translocation assay.
[0084] In some embodiments, in the optimization procedure described
above, the 3-mercapto-pyrrolidine-2,5-dione scaffold of Formula I
was fixed, and the X, Y, and Z groups in the structure were varied.
This is different from the classical SAR optimization method, in
which a series of the lead compound analogs is synthesized via
complex and time-consuming synthetic procedures. The inventors
searched for analogues of Compound 41 in the existing small
molecule libraries, including Zinc, Specs, and other libraries. In
addition, PubChem searching pool was used for identification of
analogous structures. Some selected compounds (Compounds 52-74) are
shown in Table 2.
TABLE-US-00002 TABLE 2 Exemplary structures of the compounds
optimized from the lead Compound 41 and their inhibitory activity
on CRAC channel. Compound IC.sub.50 of the Number Compound
Structure compounds 52 ##STR00057## >200 53 ##STR00058## 13.0 54
##STR00059## >200 55 ##STR00060## >200 56 ##STR00061##
>200 57 ##STR00062## >200 58 ##STR00063## >200 59
##STR00064## >200 60 ##STR00065## >200 61 ##STR00066##
>200 62 ##STR00067## 11.28 63 ##STR00068## 74.38 64 ##STR00069##
24.89 65 ##STR00070## 30.57 66 ##STR00071## 10.47 67 ##STR00072##
>200 68 ##STR00073## >200 69 ##STR00074## 107.9 70
##STR00075## >200 71 ##STR00076## >200 72 ##STR00077##
>200 73 ##STR00078## >200 74 ##STR00079## >200 75
##STR00080## >200 76 ##STR00081## >200 77 ##STR00082##
>200 78 ##STR00083## >200 79 ##STR00084## 11.67 80
##STR00085## >200 81 ##STR00086## >200 82 ##STR00087## 22.35
83 ##STR00088## >200 84 ##STR00089## >200 85 ##STR00090##
>200 86 ##STR00091## 6.34 87 ##STR00092## 0.95 88 ##STR00093##
>200 89 ##STR00094## >200 90 ##STR00095## >200 91
##STR00096## >200 92 ##STR00097## >200 93 ##STR00098##
>200 94 ##STR00099## >200 95 ##STR00100## >200 96
##STR00101## 10.89 97 ##STR00102## >200 98 ##STR00103## 21.21 99
##STR00104## 18.17 100 ##STR00105## 14.82 101 ##STR00106## 11.21
102 ##STR00107## 9.20 103 ##STR00108## 15.84 104 ##STR00109##
>200 105 ##STR00110## >200 106 ##STR00111## 5.01 107
##STR00112## >200 108 ##STR00113## >200 109 ##STR00114##
>200 110 ##STR00115## >200 111 ##STR00116## 1.60 112
##STR00117## 0.20 113 ##STR00118## 5.83 114 ##STR00119## >200
115 ##STR00120## 5.84 116 ##STR00121## >200 117 ##STR00122##
>200 118 ##STR00123## >200 119 ##STR00124## >200 120
##STR00125## >200
[0085] In some embodiments, the CRAC channel inhibitors described
herein have the general structure of Formula I:
##STR00126##
wherein
[0086] X is an optionally substituted alkyl, an optionally
substituted heterocyclyl, an optionally substituted aryl, or an
optionally substituted heteroaryl;
[0087] Y is an optionally substituted alkyl, an optionally
substituted heterocyclyl, an optionally substituted aryl, or an
optionally substituted heteroaryl; and
[0088] Z is an optionally substituted alkyl, an optionally
substituted heterocyclyl, an optionally substituted aryl, or an
optionally substituted heteroaryl.
[0089] In some embodiments of Formula I, X is an optionally
substituted C6-C10 aryl or an optionally substituted C5-C10
heteroaryl;
[0090] Y is an optionally substituted C1-C8 alkyl, an optionally
substituted C6-C10 aryl-C1-C8 alkyl, an optionally substituted
C5-C10 heteroaryl-C1-C8 alkyl, an optionally substituted C3-C10
heteroalkyl, an optionally substituted C3-C6 heterocyclyl, an
optionally substituted C6-C10 aryl, or an optionally substituted
C5-C10 heteroaryl; and
[0091] Z is an optionally substituted C6-C10 aryl or an optionally
substituted C5-C10 heteroaryl.
[0092] In some embodiments of Formula I, X is an optionally
substituted phenyl. In some embodiments, X is a phenyl substituted
with one or more groups selected from halogen, C1-C6 alkyl,
carboxyl, alkoxycarbonyl, amido, or a combination thereof. In some
embodiments, X is an unsubstituted phenyl.
[0093] In some embodiments of Formula I, X is an optionally
substituted C5 or C6 heteroaryl, such as thiophenyl, pyridyl, or
pyrimidinyl. In some embodiments of Formula I, X is a C5 or C6
hereroaryl substituted with one or more groups selected from
halogen, C1-C6 alkyl, carboxyl, alkoxycarbonyl, amido, or a
combination thereof. In some embodiments of Formula I, X is a
4-substituted phenyl, wherein the substituent is an optionally
substituted C1-C6 alkyl, COOH, COOR.sup.2, CONH.sup.2, or
CONHR.sup.2, wherein R.sup.2 is an optionally substituted C1-C6
alkyl
[0094] In some embodiments, the CRAC channel inhibitors described
herein have the structure of Formula II:
##STR00127##
[0095] wherein
[0096] R.sup.1 is H, an optionally substituted C1-C6 alkyl, COOH,
COOR.sup.2, CONH.sub.2, or CONHR.sup.2;
[0097] R.sup.2 is an optionally substituted C1-C6 alkyl;
[0098] Y is an optionally substituted C1-C8 alkyl, an optionally
substituted C6-C10 aryl-C1-C8 alkyl, or an optionally substituted
C5-C10 heteroaryl-C1-C8 alkyl; and
[0099] Z is an optionally substituted C6-C10 aryl or an optionally
substituted C5-C10 heteroaryl.
[0100] In some embodiments of Formulae I or II, Y is
(CH.sub.2).sub.nAr, wherein n is an integer between 1 and 5 and Ar
is an optionally substituted C6-C10 aryl or C5-C10 heteroaryl. In
some embodiments, Y is an optionally substituted phenethyl. In some
embodiments, Y is a phenethyl substituted with 1 or 2 groups
selected from halogen, SO.sub.2NHR.sup.3, CO.sub.2R.sup.3, or
CONHR.sup.3, wherein R.sup.3 is H or C1-C6 alkyl.
[0101] In some embodiments of Formulae I or II, Y is methyl, ethyl,
propyl, n-butyl, tert-butyl, cyclopropyl, phenyl, benzyl,
4-methoxybenzyl, 3,4-dimethoxyphenyl, 4-sulfonamidophenethyl, or
5-methylbenzo[d][1,3]dioxolyl.
[0102] In some embodiments, the CRAC channel inhibitors described
herein have the structure of Formula III:
##STR00128##
[0103] wherein
[0104] R.sup.1 is H, an optionally substituted C1-C6 alkyl, COOH,
COOR.sup.2, CONH.sub.2, or CONHR.sup.2;
[0105] R.sup.2 is an optionally substituted C1-C6 alkyl;
[0106] R.sup.4 is H or an optionally substituted C1-C6 alkyl;
[0107] R.sup.5 is H or an optionally substituted C1-C6 alkyl;
and
[0108] Z is an optionally substituted C6-C10 aryl, or an optionally
substituted C2-C10 heteroaryl.
[0109] In some embodiments of Formulae I, II, or III, Z is phenyl,
4-halophenyl, 3-trifluoromethyl-phenyl, 2,5-dichlorophenyl,
3-chloro-4-methyl-phenyl, 2-methoxyphenyl,
4-methoxycarbonyl-phenyl, benzo[d][1,3]dioxolyl,
3,5-dichlorophenyl, 3-methoxyphenyl, or 3-halophenyl.
[0110] In some embodiments of Formula III, R.sup.4 and R.sup.5 are
H.
[0111] In some embodiments, the condition treatable by inhibition
of CRAC channel activity is an immune system disease, a
hyperplastic disease, or cancer. In some embodiments, the condition
is colon cancer, breast cancer, leukemia, or glioma. In some
embodiments, the condition is an organ or a tissue transplant
rejection.
[0112] The activity CRAC channel inhibitory activity of the
compounds of Formulae I, II, or III disclosed herein can be
determined in vitro, for example, using a GFP-NFAT translocation
assay method as described below.
[0113] Using the GFP-NFAT translocation assay method, the
inhibitory activity of the selected compounds at 200 .mu.M
concentration was evaluated. As demonstrated in Table 2, several
compounds showed good inhibition of CRAC channel, for example,
Compounds 53, 62, 65, and 66. Then, IC.sub.50 values were
calculated, with Compound 53 having the lowest IC.sub.50 at 8.14
.mu.M. This IC.sub.50 value demonstrates an order of magnitude,
e.g., about tenfold, improvement compared to the IC.sub.50 of the
lead Compound 41 (shown in Table 1). Based on the result, a series
of Compound 53 analogues was designed and synthesized de novo. The
structures of several exemplary synthesized compounds (Compounds
75-104) are shown in Table 2.
[0114] The compounds described herein showed good inhibitory
activity on CRAC channel. Analyzing the structure and activity
relationship, it was found that group Y in Formula I is important
for activity. In some embodiments, retaining the
4-sulfonamide-phenethyl group resulted in the preservation of the
compound activity. In certain embodiments, if 3-substituted
2,5-pyrrolidinedione core structure was disrupted, the inhibitory
activity disappeared.
Pharmaceutical Application of Compounds
[0115] The association of dysfunction of CRAC channel activity with
various diseases such as cancer and autoimmune diseases has been
validated in the literature. Therefore, in the following
experiments, the activity of these compounds was evaluated in
different models, and it was found that exemplary compounds of the
disclosure, Compounds 53 and 87, significantly inhibit cytokine
IL-2 expression in primary T cells, with the calculated IC.sub.50
of 15.6.+-.1.17 .mu.M and 0.86.+-.0.12 .mu.M respectively (as shown
in FIGS. 9A-9F). In addition, the antitumor effect of these
compounds was also tested in different cancer cell models,
including a leukemia cell line (Jurkat cells), a breast cancer cell
line (MDA-MB-231), and a glioma cell line (U87). Compound 87 can
induce cell cycle arrest at G0 stage in Jurkat (FIG. 11B) and U87
cells (FIG. 12B) compared to their respective controls (FIGS. 11A
and 12A). Compound 53 can also inhibit IL-2 and IFN.gamma.
expression in Jurkat cell (FIG. 10). In a wound healing assay,
representative compounds of the disclosure, Compounds 53, 65, 66,
and 87, can greatly inhibit MDA-MB-231 cell migration (as shown in
FIGS. 13A and 13B). Meanwhile, representative compounds of the
disclosure, Compounds 53 and 87 can greatly inhibit the MDA-MB-231
cell invasion (FIG. 13C). In the azoxymethane-induced mouse colon
cancer model, representative compound of the disclosure, Compound
53, can greatly decrease the number of the formed tumors in the
colon, and the activity is also better than the positive control
drug CsA (as demonstrated in FIGS. 14A and 14B).
[0116] These results indicate that blocking CRAC channel function,
e.g., by compounds of Formulae I-III, can produce a therapeutic
effect. For example, the compounds in the invention can be
particularly useful to treat one or more of the following diseases:
1) immune system diseases, 2) hyperplastic diseases, and 3) cancer.
Additionally, in some embodiments, the compounds can be used to
suppress or prevent transplant immune rejection reaction.
[0117] Thus, in another aspect, disclosed herein is a method of
treatment of a condition associated with an abnormal CRAC channel
activity in a subject in need thereof, comprising administering to
the subject an amount of a CRAC channel inhibitory agent in the
amount effective to inhibit CRAC channel, wherein the CRAC channel
inhibitory agent is a compound of Formula I, Formula II, or Formula
III. In some embodiments, the CRAC channel inhibitor is Compound
41, 53, 62, 63, 64, 65, 66, 69, 79, 86, 87, 98, 99, 100, 101, 102,
103, 106, 111, 112, or 113. In some embodiments, the CRAC channel
inhibitor is Compound 53 or 87.
[0118] Specifically, the compounds disclosed herein, e.g.,
compounds of Formulae I, II, or III, can be used to treat the
immune system diseases. In some embodiments, the immune system
diseases include but are not limited to autoimmune diseases and the
related inflammation, such as systemic lupus erythematosus,
rheumatoid arthritis, systemic vasculitis, scleroderma,
dermatomyositis, multiple sclerosis, autoimmune hemolyticanemia,
thyroiditis, ulcerative colitis, eczema, psoriasis, vasculitis,
pancreatitis, myasthenia gravis, glomerulonephritis, allergy,
allergic inflammation (allergic rhinitis), asthma, uveitis,
neurogenic inflammation, and diabetes type 1.
[0119] In particular embodiments, the compounds of the invention
can be applied to treat hyperplastic diseases, including but not
limited to cardiac hypertrophy, benign prostatic hyperplasia,
familial adenomatous polyposis, neurofibromatosis, psoriasis,
hypertrophic scar, myelodysplastic syndromes, cystic fibrosis, and
atherosclerosis hamper.
[0120] In other embodiments, the compounds of the invention can be
used to treat various types of cancers, including but not limited
to leukemia, lymphoma, breast cancer, prostate cancer, liver
cancer, lung cancer, colon cancer, skeletal muscle, cervical
cancer, nasopharyngeal cancer, epidermoid cancer, esophageal
cancer, pancreatic cancer, thyroid cancer, rhabdomyosarcoma,
glioma, osteosarcoma, neuroblastoma, astrocytoma, and
schwannoma.
[0121] In certain embodiments, the compounds of Formulae I, II, or
III can suppress the immune rejection in transplant, such as organ,
marrow, stem cell, or other tissues or cell transplant.
[0122] In other embodiments, the compounds of the Formulae I, II,
or III can be used as their pharmaceutically acceptable salts,
solvates, or hydrates.
[0123] Preparation of pharmaceutical salts is well known to those
persons skilled in the art. When there is an acidic group present
in the structure of a pharmaceutically active compound, such as the
compounds of the present invention, pharmaceutically acceptable
salts can be prepared by contacting the compound with a nontoxic
inorganic base, including potassium, sodium, calcium, ammonium,
lithium, ferric, copper, and magnesium hydroxides. In some
embodiments, pharmaceutically acceptable salts can be prepared by
contacting the compound with a nontoxic organic base, including but
not limited to arginine, betaine, histidine, N-methyl glucamine,
lysine, L-glucamine and others. In some embodiments, when a basic
group is present in the structure of a pharmaceutically active
compound, such as the compounds of the present invention,
pharmaceutically acceptable salts can be prepared by contacting the
compound with a nontoxic acid, for example, hydrochloric,
hydrobromic, sulfuric, acetic, phosphoric, tartaric, citric,
fumatric, nitric, gluconic, malic, glutamic, and succinic
acids.
[0124] Pharmaceutical solvates or hydrates of the compounds of the
present invention can be formed by freeze-drying the solutions of
the compounds in water or any other suitable solvent, e.g.,
ethanol, methanol, DMSO, acetic acid, isopropanol, ethyl acetate,
ethanolamine. The general methods of preparation of solvates and
hydrates method are well known to persons skilled in the art.
[0125] In certain embodiments, the compounds of the invention, or
their pharmaceutical salts, solvates, or hydrates can be
administered in their pure form. However, more typically, it is
desirable to administer a pharmaceutical agent in the form of a
pharmaceutical composition, wherein the composition comprises the
active ingredient and one or more pharmaceutically acceptable
carriers or excipients. In some embodiments, inclusion of such
carriers or excipients does not affect the activity of compounds in
the invention. Specifically, the pharmaceutical carriers include
but are not be limited to water, saline, glucose, buffer, glycerol,
ethanol, olive oil, peanut oil, and other ingredients. In some
embodiments, pharmaceutical excipients include but not to be
limited to binders (e.g., dextrin, hydroxypropyl methylcellulose,
polyvinyl pyrrolidone), fillers (e.g., lactose, starch,
microcrystalline cellulose), disintegrating agents (e.g.,
croscarmellose sodium), lubricants (e.g., magnesium stearate),
glidants (e.g., colloidal silicon dioxide), surfactants (e.g.,
tween), solubilizers (e.g., PEG), antiseptics, flavoring agents,
etc. In some instances, the carriers and/or excipients are
compounds or ingredients designated as GRAS by the FDA. Formulation
of active pharmaceutical ingredients is well known to the persons
skilled in the art.
[0126] Suitable pharmaceutical compositions include but not limited
to a tablet, a pill, a granule, a capsule, a power, a syrup, an
emulsion, a topical cream, a suppository, a suspension, an
ointment, an inhalant, a patch, a gel, and an injectable. In some
embodiments, the compositions are sustained release formulas. A
person skilled in the art is able to select the appropriate type of
the pharmaceutical composition and/or formulation depending on the
administration route.
[0127] The modes of administration include but are not be limited
to oral, intravenous, subcutaneous, intramuscular, rectal, and
parenteral. The amounts of the active ingredients that can be
combined with pharmaceutical carriers or excipients to form single
doses vary depending on the host to be treated and the mode of
administration. In some instances, the suggested dose can range
from about 0.001 mg/kg to about 100 mg/kg each and 1-3 times intake
daily. In some embodiments, the active ingredient, e.g., one of the
presently described compounds, can also be administered in
combination with one or more other pharmaceutical agents to
increase the efficacy of the treatment.
EXAMPLES
[0128] As can be appreciated from the disclosure above, the present
invention has a wide variety of applications. The invention is
further illustrated by the following examples, which are only
illustrative and are not intended to limit the definition and scope
of the invention in any way.
Example 1
Synthesis of Representative Compounds
(1) Synthesis of (Z)-methyl
4-(3-((N-methyl-N'-phenylcarbamimidoyl)thio)-2,5-dioxopyrrolidin-1-yl)ben-
zoate
##STR00129##
[0129] Synthesis of 1-methyl-3-phenylthiourea
[0130] To a solution of methylamine hydrochloride (1.35 g) in THF
(50 mL), triethylamine (3.06 mL) and phenyl isothiocyanate (2.56
mL) were added respectively, and the mixture was stirred for 5 hrs
at room temperature, and then concentrated. The concentrate was
purified by column chromatography on silica gel to afford white
solid (3.20 g, 96%), m.p. 90-92.degree. C. .sup.1H NMR (400 MHz,
DMSO): .delta. (ppm) 9.45 (1H, s), 7.67 (1H, s), 7.32 (4H, m), 7.11
(1H, m), 2.91 (3H, d, J=4.4 Hz); MS (ES) [M+H].sup.+ 167.2.
Synthesis of
(Z)-4-((4-(methoxycarbonyl)phenyl)amino)-4-oxobut-2-enoic Acid
[0131] A mixture of maleic anhydride (1.96 g) and methyl
4-aminobenzoate (3.02 g) in THF (60 mL) was stirred at room
temperature for 3 hrs, and the precipitate was filtered off, washed
with ethyl acetate and dried to give light yellow powder (4.73 g,
95%), m.p. 190-192.degree. C. .sup.1H NMR (400 MHz, DMSO) .delta.
(ppm) 10.63 (1H, s), 7.92 (2H, d, J=8.70 Hz), 7.75 (2H, d, J=8.70
Hz), 6.45 (1H, d, J=12.00 Hz), 6.33 (1H, d, J=12.00 Hz), 4.27 (2H,
q), 1.29 (3H, t); MS (ES) [M+H].sup.+ 250.3.
Synthesis of methyl
4-(3-bromo-2,5-dioxopyrrolidin-1-yl)benzoate
[0132] Acetyl bromide (0.34 mL) was added to the suspension of
(Z)-4-((4-(methoxycarbonyl)phenyl)amino)-4-oxobut-2-enoic acid (996
mg) in ethyl acetate. The mixture was stirred at 30.degree. C. for
2 hrs, and then heated to reflux for 10 hrs. The solvent was
concentrated and the residue was purified by column chromatography
on silica gel to afford white solid (690 mg, 56%), m.p.
154-156.degree. C. .sup.1H NMR (400 MHz, DMSO): .delta. (ppm) 8.12
(2H, d, J=8.0 Hz), 7.51 (2H, d, J=8.0 Hz), 5.22-5.19 (1H, m), 3.89
(3H, s), 3.66-3.59 (1H, m), 3.21-3.16 (1H, m); MS (ES) [M+H].sup.+
167.2.
Synthesis of (Z)-methyl
4-(3-((N-methyl-N'-phenylcarbamimidoyl)thio)-2,5-dioxopyrrolidin-1-yl)ben-
zoate
[0133] The mixture of 1-methyl-3-phenylthiourea (83 mg) and methyl
4-(3-bromo-2,5-dioxopyrrolidin-1-yl)benzoate (156 mg) in THF (3 mL)
was stirred at reflux for 6 hrs, and the solvent was concentrated.
The residue was purified by column chromatography on silica gel to
afford white solid (120 mg, 61%), m.p. 191-192.degree. C. 1H NMR
(400 MHz, DMSO): .delta. (ppm) 7.92 (2H, d, J=8.0 Hz), 7.78 (2H, d,
J=8.0 Hz), 7.62 (2H, d, J=8.0 Hz), 7.46 (2H, d, J=8.0 Hz),
7.36-7.30 (2H, m), 7.10 (1H, t, J=8.0 Hz), 6.81 (2H, d, J=8.0 Hz),
4.56-4.53 (1H, m), 4.04-4.01 (2H, m), 3.81 (3H, s), 3.30-3.25 (1H,
m), 3.06 (1H, t, J=8.0 Hz), 2.96-2.89 (1H, m); MS (ES) [M+H]+
398.2.
(2) Synthesis of (Z)-methyl
4-(3-((N'-(2-methoxyphenyl)-N-methylcar-bamimidoyl)thio)-2,5-dioxopyrroli-
din-1-yl)benzoate
##STR00130##
[0134] Synthesis of
4-(2-(3-(4-methoxyphenyl)thioureido)ethyl)benzenesulfonamide
[0135] To a mixture of 1,1'-thiocarbonyl diimidazole (320 mg) and
p-anisidine (180 mg) in DMF (3 mL),
4-(2-aminoethyl)benzenesulfonamide (330 mg) was added, and the
mixture was stirred at room temperature for 5 hrs. Then water was
added and the mixture was extracted with EtOAc. The organic layers
were combined, washed with water and brine respectively, dried over
Na.sub.2SO.sub.4, filtered, and concentrated in vacuo to give white
solid powder (510 mg, 93%), m.p. 160-162.degree. C. .sup.1H NMR
(400 MHz, DMSO): .delta. (ppm) 9.61 (s, 1H), 7.86 (s, 1H), 7.76 (d,
J=8.0 Hz, 2H), 7.62 (d, J=8.0 Hz, 2H), 7.43 (d, J=8.0 Hz, 2H), 7.31
(s, 2H), 7.19 (d, J=8.0 Hz, 2H), 3.93 (s, 3H), 3.72-3.69 (m, 2H),
2.94 (t, J=7.4 Hz, 2H); MS (ES) [M+H].sup.+ 365.3.
Synthesis of (E)-methyl
4-(3-((N'-(4-methoxyphenyl)-N-(4-sulfamoylphenethyl)-carbamimidoyl)thio)--
2,5-dioxopyrrolidin-1-yl)benzoate
[0136] A mixture of
4-(2-(3-(4-methoxyphenyl)thioureido)ethyl)benzenesulfonamide (183
mg) and methyl 4-(3-bromo-2,5-dioxopyrrolidin-1-yl)benzoate (156
mg) in THF (3 mL) was stirred at reflux for 6 hrs, and the solvent
was concentrated. The residue was purified by column chromatography
on silica gel to afford white solid (197 mg, 66%), m.p.
176-178.degree. C. .sup.1H NMR (400 MHz, DMSO): .delta. (ppm) 10.49
(1H, s), 7.92 (2H, d, J=8.0 Hz), 7.78 (2H, d, J=8.0 Hz), 7.68 (2H,
d, J=8.0 Hz), 7.46 (2H, d, J=8.0 Hz), 7.36-7.30 (2H, m), 6.91 (2H,
d, J=8.0 Hz), 6.79 (2H, d, J=8.0 Hz), 4.02 (2H, t, J=8.0 Hz), 3.82
(3H, s), 3.73 (3H, s), 3.31-3.26 (1H, m), 3.06 (1H, t, J=8.0 Hz),
2.96-2.89 (1H, m); MS (ES) [M+H].sup.+597.2.
Example 2
Biological Effects of Representative Compounds
[0137] Cell Proliferation Assay
[0138] The cell proliferation was measured using the WST-1
proliferation assay kit. Briefly, an amount of 5-6.times.10.sup.3
cells per well were seeded in 96-well plates with a total volume of
100 .mu.L. After culturing overnight, cells were treated with
varying concentrations of compounds for 24 h at 37.degree. C. with
5% CO.sub.2. Then, 10 .mu.L of WST-1 reagents were added to each
well and the plate was incubated for another 2 h. The absorbance of
each well was measured on a microplate reader at a test wavelength
460 nm. The inhibitory rate was calculated with the following
equation: inhibition rate=100%.times.(OD control well-OD treated
well)/(OD control well-OD blank well). Then inhibition curves were
fit using GraphPad Prism 5 software and IC.sub.50 (defined as the
drug concentration that required for inhibiting growth by 50%
relative to controls) was calculated.
[0139] Cell Cycle Analysis
[0140] Cells were treated with or without compounds at 37.degree.
C. with 5% CO.sub.2. After incubation for 24 h, cells were
collected by trypsinization and fixed with cold 95% ethanol over 30
min at 4.degree. C. Subsequently, the cell suspension was
centrifuged at 1000 rmp/5 min, and washed with PBS one time. The
cell pellets were resuspended in 0.4 mL PBS and treated with RNAase
A (0.1 mg/mL) at 37.degree. C. for 30 min. Then, propidium iodine
(50 .mu.g/mL, PI) was added and the cells were stained for 30 min
at 37.degree. C. Analysis of cellular DNA content was performed by
flow cytometry.
[0141] Migration Assay
[0142] The effect of compounds on inhibiting migration was
evaluated using wound healing assay. Briefly, cells were seeded in
a six well-plate, and a wound was generated by scratching the cell
monolayer with a 200 .mu.L pipette tip. Then, cells were continued
to be cultured in the presence or absence of compounds, and the
photographic recording was performed at 0 h, 24 h, and 48 h
respectively. The number of the migrated cells was calculated with
ImageJ software.
[0143] Effect of Compounds on Cytokine Expression
[0144] The lymph nodes and a spleen from mouse were collected, and
then the immune cells were induced to differentiate towards Th1
cells in presence of .alpha.-CD3, .alpha.-CD28, IL-12, and IL-2.
After obtaining Th1 cells, the cells were amplified and then the
cells were treated with drugs. The expression level of the cytokine
was analyzed using flow cytometry.
[0145] Antitumor Effect of Compounds on Azoxymethane (AOM)-Induced
Mouse Colon Cancer Model
[0146] To induce colon cancer in situ, mice (four month old) were
randomly divided into three groups: (1) AOM control group; (2)
Compound 53 group, (3) CsA group, and injected with AOM
subcutaneously (10 mg/kg body weight) once a week for 4 weeks.
Then, Compound 53 and CsA group were treated with Compound 53 and
CsA respectively for 8 weeks, and the control group was treated
with 0.9% NaCl solution. Then, mice were killed and the colon was
isolated. The number of the tumors formed was analyzed.
Representative results are shown in FIGS. 14A and 14B,
demonstrating that Compound 53, an exemplary CRAC inhibitor,
demonstrated activity in this in vivo model by reducing the number
of tumors formed compared to the control group.
[0147] While illustrative embodiments have been illustrated and
described, it will be appreciated that various changes can be made
therein without departing from the spirit and scope of the
invention.
Sequence CWU 1
1
11299PRTArtificial SequenceSynthetic 1Met His Pro Glu Pro Ala Pro
Pro Pro Ser Arg Ser Ser Pro Glu Leu1 5 10 15Pro Pro Ser Gly Gly Ser
Thr Thr Ser Gly Ser Arg Arg Ser Arg Arg 20 25 30Arg Ser Gly Asp Gly
Glu Pro Pro Gly Ala Pro Pro Pro Pro Ser Ala 35 40 45Val Thr Tyr Pro
Asp Gln Ile Gly Gln Ser Tyr Ser Glu Val Met Ser 50 55 60Leu Asn Glu
His Ser Met Gln Ala Leu Ser Trp Arg Lys Leu Tyr Leu65 70 75 80Ser
Arg Ala Lys Leu Lys Ala Ser Ser Arg Thr Ser Ala Leu Leu Ser 85 90
95Gly Phe Ala Met Val Ala Met Val Glu Val Gln Leu Asp Ala Asp His
100 105 110Asp Tyr Pro Pro Gly Leu Leu Ile Ala Phe Ser Ala Cys Thr
Thr Val 115 120 125Leu Val Ala Val His Leu Phe Ala Leu Met Ile Ser
Thr Cys Ile Leu 130 135 140Pro Asn Ile Glu Ala Val Ser Asn Val His
Asn Leu Asn Ser Val Lys145 150 155 160Glu Ser Pro His Glu Arg Met
His Arg His Ile Glu Leu Ala Trp Ala 165 170 175Phe Ser Thr Val Ile
Gly Thr Leu Leu Phe Leu Ala Glu Val Val Leu 180 185 190Leu Cys Trp
Val Lys Phe Leu Pro Leu Lys Lys Gln Pro Gly Gln Pro 195 200 205Arg
Pro Thr Ser Lys Pro Pro Ala Ser Gly Ala Ala Ala Val Ser Thr 210 215
220Ser Gly Ile Thr Pro Gly Gln Ala Ala Ala Ile Ala Ser Thr Thr
Ile225 230 235 240Met Val Pro Phe Gly Leu Ile Phe Ile Val Phe Ala
Val His Phe Tyr 245 250 255Arg Ser Leu Val Ser His Lys Thr Asp Arg
Gln Phe Gln Glu Leu Asn 260 265 270Glu Leu Ala Glu Phe Ala Arg Leu
Gln Asp Gln Leu Asp His Arg Gly 275 280 285Asp His Pro Leu Leu Thr
Pro Gly Ser His Tyr 290 295
* * * * *