Inhibitors of calcium-activated chloride channels

Abstract

Provided herein are methods for identifying compounds that are inhibitors of a calcium-activated chloride channel. Aminothiophene and aminothiazole compounds, and compositions comprising these compounds, described herein that inhibit efflux of chloride through a calcium-activated chloride channel are useful for treating diseases, disorders, and sequalae of diseases, disorders, and conditions that are associated with aberrantly increased chloride and fluid secretion, for example, secretory diarrhea.

1 . A composition comprising a physiologically acceptable excipient and a compound having the following structure (I): 
       
         
           
           
               
               
           
         
       
       or a pharmaceutically acceptable salt, prodrug or stereoisomer thereof,
 wherein 
 R 1  is hydrogen or optionally substituted alkyl; 
 R 2  is hydroxy, optionally substituted alkoxy, or optionally substituted phenylamino; 
 R 3  is optionally substituted alkyl, optionally substituted alkenyl, optionally substituted cycloalkyl, optionally substituted phenyl, or optionally substituted heterocyclyl; and 
 n is 0, 1, or 2, and 
 
       wherein the compound of structure I comprises at least one —COOH. 
     
     
         2 . The composition of  claim 1  wherein the compound has the following structure I(A): 
       
         
           
           
               
               
           
         
       
       wherein n is 1 or 2. 
     
     
         3 . The composition of  claim 1 , wherein n is 1 and R 1  is hydrogen, tert-butyl, or tert-pentyl, and the compound has the following structure (Ia), (Ib), or (Ic): 
       
         
           
           
               
               
           
         
       
     
     
         4 . The composition of  claim 1 , wherein R 2  is —OR 4  wherein R 4  is hydrogen or optionally substituted C 1-6  alkyl; or phenylamino optionally substituted with C 1-6  alkoxy or C 1-6  alkyl. 
     
     
         5 . The composition of  claim 1 , wherein R 2  is —OR 4  and R 4  is hydrogen, methyl, or ethyl; or R 2  is phenylamino optionally substituted with methoxy or methyl. 
     
     
         6 . The composition of  claim 1 , wherein R 3  is optionally substituted furanyl; optionally substituted C 1 -C 6  alkyl; optionally substituted C 1 -C 6  alkenyl; optionally substituted cyclohexyl; phenyl; or phenyl substituted with halo, C 1-6  alkyl, C 1-6  alkoxy, or —COOH. 
     
     
         7 . The composition of  claim 1 , wherein
 (a) R 3  is —(CH 2 ) 2 C(═O)OH or —CH═CHC(═O)OH;   (b) R 3  is phenyl substituted with chloro, methyl, or methoxy; or   (c) R 3  is cyclohexyl substituted with —COOH.   
     
     
         8 .- 9 . (canceled) 
     
     
         10 . The composition of  claim 1 , wherein n is 1 and R 2  is —OR 4  wherein R 4  is hydrogen or optionally substituted C 1-6  alkyl, and the compound has the following structure (Id): 
       
         
           
           
               
               
           
         
       
     
     
         11 . The composition of  claim 10  wherein R 4  is hydrogen, methyl, or ethyl. 
     
     
         12 . The composition of  claim 10 , wherein R 1  is hydrogen, tert-butyl, or tert-pentyl. 
     
     
         13 . The composition of  claim 10 , wherein R 3  is optionally substituted furanyl; optionally substituted C 1 -C 6  alkyl; optionally substituted C 1 -C 6  alkenyl; optionally substituted cyclohexyl; phenyl; or phenyl substituted with halo, C 1-6  alkyl, C 1-6  alkoxy, or —COOH. 
     
     
         14 . The composition of  claim 10 , wherein R 3  is —(CH 2 ) 2 C(═O)OH; —CH═CHC(═O)OH; phenyl substituted with chloro, methyl, or methoxy; or cyclohexyl substituted with —COOH. 
     
     
         15 . The composition of  claim 1 , wherein n is 1 and the compound has any one of the following structures (Ie), (If), (Ig), or (Ih): 
       
         
           
           
               
               
           
         
       
       wherein Y is optionally substituted C 1 -C 6  alkylene or optionally substituted C 1 -C 6  alkenylene; R 5  is hydrogen or optionally substituted C 1-4  alkyl; and R 6  is hydrogen, optionally substituted alkyl, optionally substituted alkoxy, —COOH, or halo. 
     
     
         16 . The composition of  claim 15  wherein R 6  is hydrogen, halo, C 1-6  alkyl, C 1-6  alkoxy, or —COOH. 
     
     
         17 . The composition of  claim 15  wherein R 6  is hydrogen, chloro, methyl, or methoxy. 
     
     
         18 . The composition of  claim 15 , wherein R 1  is hydrogen, tert-butyl, or tert-pentyl; and R 2  is —OR 4  wherein R 4  is hydrogen or optionally substituted C 1-6  alkyl. 
     
     
         19 . The composition of  claim 18  wherein R 4  is hydrogen, methyl, or ethyl. 
     
     
         20 . The composition of  claim 15 , wherein R 2  is phenylamino optionally substituted with methoxy or methyl. 
     
     
         21 . The composition of  claim 1 , wherein n is 2; R 1  is hydrogen; R 2  is —OR 4 ; and R 3  is optionally substituted phenyl, and the compound has the following structure (Ii): 
       
         
           
           
               
               
           
         
       
       wherein R 4  is hydrogen or optionally substituted C 1-6  alkyl; and R 6  is hydrogen, optionally substituted alkyl, optionally substituted alkoxy, or halo. 
     
     
         22 . The composition of  claim 21  wherein R 4  is hydrogen, methyl, or ethyl. 
     
     
         23 . The composition of  claim 21 , wherein R 6  is hydrogen, chloro, optionally substituted C 1-6  alkyl, or optionally substituted C 1-6  alkoxy. 
     
     
         24 . The composition of  claim 21 , wherein R 6  is hydrogen, chloro, methyl, or methoxy. 
     
     
         25 . The composition of  claim 1 , wherein the compound is 6-tert-butyl-2-(furan-2-carboxamido)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acid;
 6-tert-butyl-2-(2-methylbenzamido)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acid;   6-tert-butyl-2-(3-chlorobenzamido)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acid;   2-benzamido-6-tert-butyl-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acid;   6-tert-butyl-2-(2-chlorobenzamido)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acid;   4-(6-tert-butyl-3-(ethoxycarbonyl)-4,5,6,7-tetrahydrobenzo[b]thiophen-2-ylamino)-4-oxobutanoic acid;   (E)-4-(6-tert-butyl-3-(ethoxycarbonyl)-4,5,6,7-tetrahydrobenzo[b]thiophen-2-ylamino)-4-oxobut-2-enoic acid;   2-(6-tent-butyl-3-(ethoxycarbonyl)-4,5,6,7-tetrahydrobenzo[b]thiophen-2-ylcarbamoyl)cyclohexanecarboxylic acid;   5-(6-tert-butyl-3-(methoxycarbonyl)-4,5,6,7-tetrahydrobenzo[b]thiophen-2-ylamino)-5-oxopentanoic acid;   2-(3-(ethoxycarbonyl)-6-tert-pentyl-4,5,6,7-tetrahydrobenzo[b]thiophen-2-ylcarbamoyl)cyclohexanecarboxylic acid;   4-(6-tert-butyl-3-(methoxycarbonyl)-4,5,6,7-tetrahydrobenzo[b]thiophen-2-ylamino)-4-oxobutanoic acid;   2-(4-methylbenzamido)-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophene-3-carboxylic acid;   2-benzamido-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophene-3-carboxylic acid;   2-(2-chlorobenzamido)-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophene-3-carboxylic acid;   2-(3-methoxybenzamido)-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophene-3-carboxylic acid;   4-(6-tert-butyl-3-(m-tolylcarbamoyl)-4,5,6,7-tetrahydrobenzo[b]thiophen-2-ylamino)-4-oxobutanoic acid;   2-(3-methylbenzamido)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acid; or   4-(6-tert-butyl-3-(4-methoxyphenylcarbamoyl)-4,5,6,7-tetrahydrobenzo[b]thiophen-2-ylamino)-4-oxobutanoic acid.   
     
     
         26 . A composition comprising a physiologically acceptable excipient and a compound having the following structure (II): 
       
         
           
           
               
               
           
         
       
       or a pharmaceutically acceptable salt, prodrug or stereoisomer thereof,
 wherein R 7  is optionally substituted C 1-6  alkyl, optionally substituted phenyl, or optionally substituted phenylacyl; 
 R 8  is hydrogen, optionally substituted C 1-6  alkyl, or optionally substituted phenyl; 
 R 9  and R 10  are the same or different and independently hydrogen, optionally substituted alkyl, optionally substituted alkoxy, or optionally substituted phenoxy. 
 
     
     
         27 . The composition of  claim 26  wherein at least one of R 9  and R 10  is not hydrogen. 
     
     
         28 . The composition of  claim 26 , wherein R 7  is optionally substituted phenyl and the compound has the following structure (IIa): 
       
         
           
           
               
               
           
         
       
       wherein R 11  and R 12  are the same or different and independently hydrogen, hydroxy, carboxy, halo, optionally substituted alkyl, optionally substituted alkoxy, or optionally substituted cycloalkyl. 
     
     
         29 . The composition of  claim 26 , wherein R 9  is hydrogen, optionally substituted C 1-4  alkyl, or optionally substituted C 1-4  alkoxy, or phenoxy; and R 10  is optionally substituted C 1-4  alkyl, or optionally substituted C 1-4  alkoxy, or phenoxy. 
     
     
         30 . The composition of  claim 26 , wherein
 (a) R 9  is hydrogen, C 1-4  alkyl, trifluoromethyl, methoxy, ethoxy, or phenoxy; and R 10  is C 1-4  alkyl, trifluoromethyl, methoxy, ethoxy, or phenoxy;   (b) R 9  is hydrogen and R 10  is methyl, ethyl, isobutyl, methoxy, phenoxy, or trifluoromethyl;   (c) R 9  is hydrogen and R 10  is methyl, ethyl, isobutyl, phenoxy, or methoxy, and wherein R 10  is located at the 4-position;   (d) R 9  is hydrogen and R 10  is trifluoromethyl and R 10  is located at the 3-position; or   (e) R 9  is methyl and located at the 2-position, and wherein R 10  is methyl and located at the 4-position.   
     
     
         31 .- 34 . (canceled) 
     
     
         35 . The composition of  claim 26 , wherein R 8  is hydrogen or optionally substituted C 1-6  alkyl. 
     
     
         36 . The composition of  claim 26 , wherein R 8  is hydrogen, n-propyl, —CH 2 C(═O)OH, or —(CH 2 ) 2 C(═O)OH. 
     
     
         37 . The composition of  claim 28 , wherein R 11  and R 12  are the same or different and independently hydrogen, hydroxy, carboxy, halo, optionally substituted C 1-4  alkyl, C 1-4  alkoxy, or optionally substituted cyclohexyl. 
     
     
         38 . The composition of  claim 28 , wherein R 11  is hydrogen and R 12  is hydrogen, hydroxy, carboxy, bromo, chloro, trifluoromethyl, methyl, ethyl, isobutyl, methoxy, ethoxy, or cyclohexyl. 
     
     
         39 . The composition of  claim 28 , wherein
 (a) R 11  is hydroxy and R 12  is carboxyl;   (b) R 11  is methyl and R 12  is halo; or   (c) R 11  is hydrogen and R 12  is chloro; or   (d) each of R 11  and R 12  is chloro.   
     
     
         40 .- 41 . (canceled) 
     
     
         42 . The composition of  claim 26  wherein the compound of structure II comprises at least one —COOH. 
     
     
         43 . The composition of  claim 28  wherein the compound of structure II(a) comprises at least one —COOH. 
     
     
         44 . The composition of either  claim 26 , wherein R 7  is methyl; ethyl; unsubstituted phenylacyl; phenyl; phenyl substituted with carboxy, C 1-6  alkyl, halo, optionally substituted cycloalkyl, or C 1-6  alkoxy. 
     
     
         45 . The composition of  claim 26 , wherein
 (a) R 7  is phenyl substituted with hydroxy, chloro, bromo, methyl, ethyl, trifluoromethyl, methoxy, ethoxy, or cyclohexyl;   (b) R 7  is phenyl substituted with carboxy and hydroxyl, di-halo, or C 1-6  alkyl and halo; or   (c) wherein R 7  is phenyl substituted with di-chloro or substituted with methyl and chloro.   
     
     
         46 .- 47 . (canceled) 
     
     
         48 . The composition of  claim 26  wherein R 9  is hydrogen and R 10  is methyl, trifluoromethyl, or —OR 14 ; or each of R 9  and R 10  is methyl, and the compound has the following structure (IIe), (IIf), (IIg), or (IIh): 
       
         
           
           
               
               
           
         
       
       wherein R 14  is hydrogen, optionally substituted C 1-6  alkyl, or optionally substituted phenyl. 
     
     
         49 . The composition of  claim 48  wherein R 14  is hydrogen, methyl, or unsubstituted phenyl. 
     
     
         50 . The composition of  claim 48 , wherein R 8  is hydrogen or optionally substituted C 1-6  alkyl. 
     
     
         51 . The composition of  claim 48 , wherein R 8  is n-propyl, —CH 2 C(═O)OH, or —(CH 2 ) 2 C(═O)OH. 
     
     
         52 . The composition of  claim 48 , wherein
 (a) R 7  is methyl, ethyl, unsubstituted phenylacyl, phenyl, or phenyl substituted with carboxy, C 1-6  alkyl, halo, optionally substituted cycloalkyl, or C 1-6  alkoxy;   (b) R 7  is phenyl substituted with hydroxy, chloro, bromo, methyl, ethyl, trifluoromethyl, methoxy, ethoxy, or cyclohexyl;   (c) R 7  is phenyl substituted with carboxy and hydroxy, di-halo, or C 1-6  alkyl and halo; or   (d) R 7  is phenyl substituted either with di-chloro or with methyl and chloro.   
     
     
         53 .- 112 . (canceled) 
     
     
         113 . The composition of  claim 26  wherein the compound is
 2-hydroxy-5-(4-p-tolylthiazol-2-ylamino)benzoic acid; 
 2-(2-(3-chloro-4-methylphenylamino)-4-p-tolylthiazol-5-yl)acetic acid; 
 2-(2-(3-bromophenylamino)-4-p-tolylthiazol-5-yl)acetic acid; 
 2-(2-(2,4-dichlorophenylamino)-4-p-tolylthiazol-5-yl)acetic acid; 
 2-(4-p-tolyl-2-(3-(trifluoromethyl)phenylamino)thiazol-5-yl)acetic acid; 
 4-(4-(2,4-dimethylphenyl)-5-propylthiazol-2-ylamino)benzoic acid; 
 2-(2-(4-bromophenylamino)-4-(2,4-dimethylphenyl)thiazol-5-yl)acetic acid; 
 2-(4-(2,4-dimethylphenyl)-2-(4-(trifluoromethyl)phenylamino)thiazol-5-yl)acetic acid; 
 N-(4-isobutylphenyl)-4-(4-phenoxyphenyl)thiazol-2-amine; 
 N-(4-cyclohexylphenyl)-4-(3-(trifluoromethyl)phenyl)thiazol-2-amine; 
 2-(2-(4-ethoxyphenylamino)-4-p-tolylthiazol-5-yl)acetic acid; 
 N-ethyl-4-p-tolylthiazol-2-amine; or 
 3-(4-(4-methoxyphenyl)-2-(4-methoxyphenylamino)thiazol-5-yl)propanoic acid. 
 
     
     
         114 . A method of inhibiting a calcium-activated chloride channel comprising: contacting (a) a cell that comprises the calcium-activated chloride channel and (b) the composition according to  claim 1 , in an amount effective to inhibit activation of the channel. 
     
     
         115 . The method of  claim 114 , wherein the cell is an epithelial cell. 
     
     
         116 . The method of  claim 115  wherein the epithelial cell is an intestinal epithelial cell or a lung epithelial cell. 
     
     
         117 . The method of  claim 115  wherein the calcium-activated chloride channel is TMEM16A. 
     
     
         118 . A method of inhibiting a calcium-activated chloride channel comprising: contacting (a) a cell that comprises the calcium-activated chloride channel and (b) the composition according to  claim 26 , in an amount effective to inhibit activation of the channel. 
     
     
         119 . The method of  claim 118 , wherein the cell is an epithelial cell. 
     
     
         120 . The method of  claim 119  wherein the epithelial cell is an intestinal epithelial cell or a lung epithelial cell. 
     
     
         121 . The method of  claim 119  wherein the calcium-activated chloride channel is TMEM16A. 
     
     
         122 . A method of treating a disease or disorder associated with abnormally increased chloride ion secretion, said method comprising administering to a subject a composition according to  claim 1 , in an amount effective to inhibit a calcium-activated chloride channel, thereby inhibiting chloride ion secretion. 
     
     
         123 . The method of  claim 122  wherein the disease or disorder is abnormally increased intestinal fluid secretion. 
     
     
         124 . The method of  claim 122  wherein the disease or disorder is secretory diarrhea. 
     
     
         125 . The method of  claim 122  wherein a condition of the disease or disorder is associated with abnormally increased mucus secretion. 
     
     
         126 . The method of  claim 125  wherein the disease or disorder is asthma, chronic obstructive pulmonary disease, bronchiectasis, or cystic fibrosis. 
     
     
         127 . A method of treating a disease or disorder associated with abnormally increased chloride ion secretion, said method comprising administering to a subject a composition according to  claim 26 , in an amount effective to inhibit a calcium-activated chloride channel, thereby inhibiting chloride ion secretion. 
     
     
         128 . The method of  claim 127  wherein the disease or disorder is abnormally increased intestinal fluid secretion. 
     
     
         129 . The method of  claim 127  wherein the disease or disorder is secretory diarrhea. 
     
     
         130 . The method of  claim 127  wherein a condition of the disease or disorder is associated with abnormally increased mucus secretion. 
     
     
         131 . The method of  claim 130  wherein the disease or disorder is asthma, chronic obstructive pulmonary disease, bronchiectasis, or cystic fibrosis. 
     
     
         132 . A method of identifying an agent that is an inhibitor of a calcium-activated chloride channel comprising:
 (a) contacting a cell and a candidate agent in a test sample to permit interaction between the candidate agent and the cell, wherein the cell comprises (i) a calcium-activated chloride channel and (ii) a cytoplasmic indicator protein that binds halide;   (b) adding to the test sample (i) at least one calcium-elevating agonist and (ii) iodide, to permit binding of the calcium-elevating agonist to the cell, wherein binding of the calcium-elevating agonist to the cell increases the level of calcium ion (Ca 2+ ) in the cell; and   (c) determining the level of iodide influx in the presence of the candidate agent and comparing the level of iodide influx in the presence of the candidate agent with the level of iodide influx in the absence of the candidate agent, wherein a decrease in the level of iodide influx in the presence of the candidate agent compared with the level of iodide influx in the absence of the candidate agent, indicates that the candidate agent is an inhibitor of the calcium-activated chloride channel.   
     
     
         133 . A method of inhibiting fluid secretion from a cell comprising administering to a subject the composition of  claim 1  in an amount effective to inhibit conductance of chloride through a calcium-activated chloride channel, thereby inhibiting fluid secretion from the cell, wherein the subject has a condition, disease, or disorder treatable by inhibiting the calcium-activated chloride channel. 
     
     
         134 . The method of  claim 133  wherein the disease or disorder is selected from abnormally increased intestinal fluid secretion, secretory diarrhea, asthma, chronic obstructive pulmonary disease, bronchiectasis, or cystic fibrosis. 
     
     
         135 . A method of inhibiting fluid secretion from a cell comprising administering to a subject the composition  claim 26  in an amount effective to inhibit conductance of chloride through a calcium-activated chloride channel, thereby inhibiting fluid secretion from the cell, wherein the subject has a condition, disease, or disorder treatable by inhibiting the calcium-activated chloride channel. 
     
     
         136 . The method of  claim 135  wherein the disease or disorder is selected from abnormally increased intestinal fluid secretion, secretory diarrhea, asthma, chronic obstructive pulmonary disease, bronchiectasis, or cystic fibrosis.