Patent Application
20100168197
This present invention generally relates to muscarinic receptor antagonists, which are useful, among other uses, for the treatment of various diseases of the respiratory, urinary and gastrointestinal systems mediated through muscarinic receptors. The invention also relates to processes for the preparation of such compounds, pharmaceutical compositions containing such compounds, and methods for treating diseases mediated through muscarinic receptors.
Physiological effects elicited by the neurotransmitter acetylcholine are mediated through its interaction with two major classes of acetylcholine receptors—the nicotinic and muscarinic acetylcholine receptors. Muscarinic receptors belong to the superfamily of G-protein coupled receptors and five molecularly distinct subtypes are known to exist (M1, M2, M3, M4 and M5).
These receptors are widely distributed on multiple organs and tissues and are critical to the maintenance of central and peripheral cholinergic neurotransmission. The regional distribution of these receptor sub-types in the brain and other organs has been documented. (for example, the M1 subtype is located primarily in neuronal tissues such as cerebral cortex and autonomic ganglia, the M2 subtype is present mainly in the heart and bladder smooth muscle, and the M3 subtype is located predominantly on smooth muscle and salivary glands (Nature, 323, (1986), 411; Science, 237, (1987), 527).
A review in Curr. Opin. Chem. Biol., 3, (1999), 426 as well as Eglen et. al., Trends in Pharmacol. Sci., 22, (2001), 409 describes the biological potential of modulating muscarinic receptor subtypes by ligands in different disease conditions, such as Alzheimer's disease, pain, urinary disease condition, chronic obstructive pulmonary disease, and the like.
The pharmacological and medical aspects of the muscarinic class of acetylcholine agonists and antagonists are presented in a review in Molecules, 6, (2001), 142. Birdsall et. al., Trends in Pharmacol. Sci., 22, (2001), 215 has also summarized the recent developments on the role of different muscarinic receptor subtypes using different muscarinic receptors of knock-out mice.
Almost all smooth muscles express a mixed population of M2 and M3 receptors. Although M2 receptors are the predominant cholinoreceptors, a smaller population of M3 receptors appears to be the most functionally important, as they mediate the direct contraction of smooth muscles. Muscarinic receptor antagonists are known to be useful for treating various medical conditions associated with improper smooth muscle function, such as overactive bladder syndrome, irritable bowel syndrome and chronic obstructive pulmonary disease. However, the therapeutic utility of antimuscarinics has been limited by poor tolerability as a result of treatment-related, frequent systemic adverse events such as dry mouth, constipation, blurred vision, headache, somnolence and tachycardia. Thus, there exists a need for novel muscarinic receptor antagonists that demonstrate target organ selectivity.
WO 2004/005252 discloses azabicyclo derivatives described as muscarinic receptor antagonists. WO 2004/004629, WO 2004/052857, WO 2004/067510, WO 2004/014853, WO 2004/014363 discloses 3,6-disubstituted azabicyclo[3.1.0]hexane derivatives described as useful muscarinic receptor antagonists. WO 2004/056811 discloses flaxavate derivatives as muscarinic receptor antagonists. WO 2004/056810 discloses xanthene derivatives as muscarinic receptor antagonists. WO 2004/056767 discloses 1-substituted-3-pyrrolidine derivatives as muscarinic receptor antagonists. WO 99/14200, WO 03/027060, U.S. Pat. No. 6,200,991, and WO 00/56718 disclose heterocycle derivatives as muscarinic receptor antagonists. WO 2004/089363, WO 2004/089898, WO 2004/069835, WO 2004/089900 and WO 2004/089364 disclose substituted azabicyclohexane derivatives as muscarinic receptor antagonists. WO 2006/018708 discloses pyrrolidine derivatives as muscarinic receptor antagonists. WO 2006/35303 discloses azabicyclo derivatives as muscarinic receptor antagonists.
J. Med. Chem., 44, (2002), 984 describes cyclohexylmethylpiperidinyl-triphenylpropioamide derivatives as selective M3 antagonists discriminating against the other receptor subtypes. J. Med. Chem., 36, (1993), 610 describes the synthesis and antimuscarinic activity of some 1-cycloalkyl-1-hydroxy-1-phenyl-3-(4-substituted piperazinyl)-2-propanones and related compounds. J. Med. Chem., 34, (1991), 3065 describes analogues of oxybutynin, synthesis and antimuscarinic activity of some substituted 7-amino-1-hydroxy-5-heptyn-2-ones and related compounds. Bio-Org. Med. Chem. Lett., 15, (2005), 2093 describes the synthesis and activities of analogues of oxybutynin and tolterodine. Chem. Pharm. Bull., 53, (4): (2005), 437 discloses thiazole carboxamide derivatives.
The present invention provides muscarinic receptor antagonists useful in the treatment of disease states associated with improper smooth muscle function and respiratory disorders.
In one aspect, there are provided muscarinic receptor antagonists, which can be useful as safe and effective therapeutic or prophylactic agents for the treatment of various diseases of the respiratory, urinary and gastrointestinal systems. Also provided are processes for synthesizing such compounds.
In another aspect, pharmaceutical compositions containing such compounds are provided together with acceptable carriers, excipients or diluents which can be useful for the treatment of various diseases of the respiratory, urinary and gastrointestinal systems.
The enantiomers, diastereomers, N-oxides, polymorphs, pharmaceutically acceptable salts and pharmaceutically acceptable solvates of these compounds as well as metabolites having the same type of activity are also provided, as well as pharmaceutical compositions comprising the compounds, their metabolites, enantiomers, diastereomers, N-oxides, polymorphs, solvates or pharmaceutically acceptable salts thereof, in combination with a pharmaceutically acceptable carrier and optionally included excipients.
Other aspects will be set forth in the description which follows, and in part will be apparent from the description or may be learnt by the practice of the invention.
In accordance with one aspect, there are provided compounds having the structure of Formula I:
and its pharmaceutically acceptable salts, pharmaceutically acceptable solvates, enantiomers, diastereomers, polymorphs or N-oxides whereinrepresents a single bond when G is —OH and double bond when G is —O;
R1 and R2 are independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, cycloalkyl, aryl, heteroaryl, heterocyclyl, heterocyclylalkyl or heteroarylalkyl;
R3 is selected from the group selected from hydrogen, hydroxy, alkoxy, alkenyloxy or alkynyloxy;
X is selected from oxygen, —NH, —NR (wherein R is alkyl, alkenyl, alkenyl, alkynyl or aryl), sulphur or no atom;
Het is heterocyclyl or heteroaryl;
n is an integer from 1 to 6;
With the proviso that when R1 and R2 are phenyl, R3 is hydroxy and X is no atom, then Het cannot be a saturated heterocyclyl group.
The following definitions apply to terms as used herein:
The term “alkyl,” unless otherwise specified, refers to a monoradical branched or unbranched saturated hydrocarbon chain having from 1 to 20 carbon atoms. Alkyl groups can be optionally interrupted by atom(s) or group(s) independently selected from oxygen, sulfur, a phenylene, sulphinyl, sulphonyl group or —NRα—, wherein Rα can be hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, aryl, acyl, aralkyl, —C(═O)ORλ, SOmRψ or —C(═O)NRλRπ. This term can be exemplified by groups such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, n-decyl, tetradecyl, and the like. Alkyl groups may be substituted further with one or more substituents selected from alkenyl, alkynyl, alkoxy, cycloalkyl, cycloalkenyl, acyl, acylamino, acyloxy, alkoxycarbonylamino, azido, cyano, halogen, hydroxy, keto, oxo, thiocarbonyl, carboxy, carboxyalkyl, aryl, heterocyclyl, heteroaryl, (heterocyclyl)alkyl, cycloalkoxy, —CH═N—O(C1-6alkyl), —CH═N—NH(C1-6alkyl), —CH═N—NH(C1-6alkyl)-C1-6alkyl, arylthio, thiol, alkylthio, aryloxy, nitro, aminosulfonyl, aminocarbonylamino, —NHC(═O)Rλ, —NRλRπ, —C(═O)NRλRπ, —NHC(═O)NRλRπ, —C(═O)heteroaryl, C(═O)heterocyclyl, —O—C(═O)NRλRπ {wherein Rλ and Rπ are independently selected from hydrogen, halogen, hydroxy, alkyl, alkenyl, alkynyl, alkenyl, alkoxy, cycloalkyl, cycloalkenyl, aryl, aralkyl, heterocyclyl, heteroaryl, heterocyclylalkyl, heteroarylalkyl or carboxy}, nitro or —SOmRψ (wherein m is an integer from 0-2 and Rψ is hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, aralkyl, aryl, heterocyclyl, heteroaryl, heteroarylalkyl or heterocyclylalkyl). Unless otherwise constrained by the definition, alkyl substituents may be further substituted by 1-3 substituents selected from alkyl, alkenyl, alkynyl, carboxy, —NRλRπ, —C(═O)NRλRπ, —OC(═O)NRπ, —NHC(═O)NRλRπ, hydroxy, alkoxy, halogen, CF3, cyano, and —SOmRψ; or an alkyl group also may be interrupted by 1-5 atoms of groups independently selected from oxygen, sulfur or —NRα— (wherein Rα, Rλ, Rπ, m and Rψ are the same as defined earlier). Unless otherwise constrained by the definition, all substituents may be substituted further by 1-3 substituents selected from alkyl, alkenyl, alkynyl, carboxy, carboxyalkyl, —NRλRπ, —C(═O)NRλRπ, —O—C(═O)NRλRπ, hydroxy, alkoxy, halogen, CF3, cyano, and —SOmRψ (wherein Rλ, Rπ, m and Rψ are the same as defined earlier); or an alkyl group as defined above that has both substituents as defined above and is also interrupted by 1-5 atoms or groups as defined above.
The term “alkenyl,” unless otherwise specified, refers to a monoradical of a branched or unbranched unsaturated hydrocarbon group having from 2 to 20 carbon atoms with cis, trans or geminal geometry. Alkenyl groups can be optionally interrupted by atom(s) or group(s) independently chosen from oxygen, sulfur, phenylene, sulphinyl, sulphonyl and —NRα— (wherein Rα is the same as defined earlier). In the event that alkenyl is attached to a heteroatom, the double bond cannot be alpha to the heteroatom. Alkenyl groups may be substituted further with one or more substituents selected from alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, cycloalkenyl, acyl, acylamino, acyloxy, —NHC(═O)Rλ, —NRλRπ, —C(═O)NRλRπ, —NHC(═O)NRλRπ, —O—C(═O)NRλRπ, alkoxycarbonylamino, azido, cyano, halogen, hydroxy, oxo, keto, carboxyalkyl, thiocarbonyl, carboxy, arylthio, thiol, alkylthio, aryl, aralkyl, aryloxy, heterocyclyl, heteroaryl, heterocyclyl alkyl, heteroaryl alkyl, aminosulfonyl, aminocarbonylamino, alkoxyamino, hydroxyamino, alkoxyamino, nitro or SOmRψ (wherein Rλ, Rπ, m and Rψ are as defined earlier). Unless otherwise constrained by the definition, alkenyl substituents optionally may be substituted further by 1-3 substituents selected from alkyl, alkenyl, alkynyl, carboxy, hydroxy, alkoxy, halogen, —CF3, cyano, —NRλRπ, —C(═O)NRλRπ, —O—C(═O)Nπ and —SOmRψ (wherein Rλ, Rπ, m and Rψ are as defined earlier). Groups, such as ethenyl or vinyl (CH═CH2), 1-propylene or allyl (—CH2CH═CH2), iso-propylene (—C(CH3)═CH2), bicyclo[2.2.1]heptene, and the like, exemplify this term.
The term “alkynyl,” unless otherwise specified, refers to a monoradical of an unsaturated hydrocarbon, having from 2 to 20 carbon atoms. Alkynyl groups can be optionally interrupted by atom(s) or group(s) independently chosen from oxygen, sulfur, phenylene, sulphinyl, sulphonyl and —NRα— (wherein Rα is the same as defined earlier). In the event that alkynyl groups are attached to a heteroatom, the triple bond cannot be alpha to the heteroatom. Alkynyl groups may be substituted further with one or more substituents selected from alkyl, alkenyl, alkoxy, cycloalkyl, cycloalkenyl, acyl, acylamino, acyloxy, alkoxycarbonylamino, azido, cyano, halogen, hydroxy, keto, oxo, thiocarbonyl, carboxy, carboxyalkyl, arylthio, thiol, alkylthio, aryl, aralkyl, aryloxy, aminosulfonyl, aminocarbonylamino, hydroxyamino, alkoxyamino, nitro, heterocyclyl, heteroaryl, heterocyclylalkyl, heteroarylalkyl, —NHC(═O)Rλ, —NRλRπ, —NHC(═O)NRλRπ, —C(═O)NRλRπ, —O—C(═O)NRλRπ or —SOmRψ (wherein Rλ, Rπ, m and Rψ are the same as defined earlier). Unless otherwise constrained by the definition, alkynyl substituents optionally may be substituted further by 1-3 substituents selected from alkyl, alkenyl, alkynyl, carboxy, carboxyalkyl, hydroxy, alkoxy, halogen, CF3, —NRλRπ, —C(═O)NRλRπ, —NHC(═O)NRλRπ, —C(═O)NRλRπ, cyano or —SOmRψ (wherein Rλ, Rπ, m and Rψ are the same as defined earlier).
The term “alkoxy” denotes the group O-alkyl wherein alkyl is the same as defined above.
The term “aryl,” unless otherwise specified, refers to aromatic system having 6 to 14 carbon atoms, wherein the ring system can be mono-, bi- or tricyclic and are carbocyclic aromatic groups. For example, aryl groups include, but are not limited to, phenyl, biphenyl, anthryl or naphthyl ring and the like, optionally substituted with 1 to 3 substituents selected from halogen (e.g., F, Cl, Br, I), hydroxy, alkyl, alkenyl, alkynyl, cycloalkyl, alkoxy, acyl, aryloxy, CF3, cyano, nitro, COORψ, NHC(═O)Rλ, —NRλRπ, —C(═O)NRλRπ, —NHC(═O)NRλRπ, —O—C(═O)NRλRπ, —SOmRψ, carboxy, heterocyclyl, heteroaryl, heterocyclylalkyl, heteroarylalkyl or amino carbonyl amino, mercapto, haloalkyl, optionally substituted aryl, optionally substituted heterocyclylalkyl, thioalkyl, —CONHRπ, —OCORπ, —CORπ, —NHSO2Rπ or SO2NHRπ (wherein Rλ, Rπ, m and Rψ are the same as defined earlier). Aryl groups optionally may be fused with a cycloalkyl group, wherein the cycloalkyl group may optionally contain heteroatoms selected from O, N or S. Groups such as phenyl, naphthyl, anthryl, biphenyl, and the like exemplify this term.
The term “aralkyl,” unless otherwise specified, refers to alkyl-aryl linked through an alkyl portion (wherein alkyl is as defined above) and the alkyl portion contains 1-6 carbon atoms and aryl is as defined below. Examples of aralkyl groups include benzyl, ethylphenyl, propylphenyl, naphthylmethyl and the like.
The term “cycloalkyl,” unless otherwise specified, refers to cyclic alkyl groups of from 3 to 20 carbon atoms having a single cyclic ring or multiple condensed rings, which may optionally contain one or more olefinic bonds, unless otherwise constrained by the definition. Such cycloalkyl groups can include, for example, single ring structures, including cyclopropyl, cyclobutyl, cyclooctyl, cyclopentenyl, and the like or multiple ring structures, including adamantanyl, and bicyclo[2.2.1]heptane or cyclic alkyl groups to which is fused an aryl group, for example, indane, and the like. Spiro and fused ring structures can also be included. Cycloalkyl groups may be substituted further with one or more substituents selected from alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, cycloalkenyl, acyl, acylamino, acyloxy, alkoxycarbonylamino, azido, cyano, halogen, hydroxy, oxo, thiocarbonyl, carboxy, carboxyalkyl, arylthio, thiol, alkylthio, aryl, aralkyl, aryloxy, aminosulfonyl, aminocarbonylamino, —NRλRπ, —NHC(═O)NRλRπ, —NHC(═O)Rλ, —C(═O)NRλRπ, —O—C(═O)NRλRπ, nitro, heterocyclyl, heteroaryl, heterocyclylalkyl, heteroarylalkyl or SOmRψ (wherein Rλ, Rπ, m and Rψ are the same as defined earlier). Unless otherwise constrained by the definition, cycloalkyl substituents optionally may be substituted further by 1-3 substituents selected from alkyl, alkenyl, alkynyl, carboxy, hydroxy, alkoxy, halogen, CF3, —NRλRπ, —C(═O)NRλRπ, —NHC(═O)NRλRπ, —OC(═O)NRλRπ, cyano or SOmRψ (wherein Rλ, Rπ, m and Rψ are the same as defined earlier). “Cycloalkylalkyl” refers to alkyl-cycloalkyl group linked through alkyl portion, wherein the alkyl and cycloalkyl are the same as defined earlier.
The term “carboxy” as defined herein refers to —C(═O)OH.
The term “aryloxy” denotes the group O-aryl, wherein aryl is as defined above.
The term “heteroaryl,” unless otherwise specified, refers to an aromatic ring structure containing 5 or 6 ring atoms or a bicyclic or tricyclic aromatic group having from 8 to 10 ring atoms, with one or more heteroatom(s) independently selected from N, O or S optionally substituted with 1 to 4 substituent(s) selected from halogen (e.g., F, Cl, Br, I), hydroxy, alkyl, alkenyl, alkynyl, cycloalkyl, acyl, carboxy, aryl, alkoxy, aralkyl, cyano, nitro, heterocyclyl, heteroaryl, —NRλRπ, CH═NOH, (CH2)wC(═O)Rη {wherein w is an integer from 0-4 and Rη is hydrogen, hydroxy, ORλ, NRλRπ, —NHORω or —NHOH}, —C(═O)NRλRπ —NHC(═O)NRλRπ, —SOmRψ —O—C(═O)NRλRπ, —O—C(═O)Rλ, or —O—C(═O)ORλ (wherein m, Rψ, Rλ and Rπ, are as defined earlier and Rψ is alkyl, cycloalkyl, aryl, heteroaryl, heterocyclyl, heteroarylalkyl or heterocyclylalkyl). Unless otherwise constrained by the definition, the substituents are attached to a ring atom, i.e., carbon or heteroatom in the ring. Examples of heteroaryl groups include oxazolyl, imidazolyl, pyrrolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, tetrazolyl, thiazolyl, oxadiazolyl, benzoimidazolyl, thiadiazolyl, pyridinyl, pyridazinyl, pyrimidinyl, pyrazinyl, thienyl, isoxazolyl, triazinyl, furanyl, benzofuranyl, indolyl, benzthiazinyl, benzthiazinonyl, benzoxazinyl, benzoxazinonyl, quinazonyl, carbazolyl phenothiazinyl, phenoxazinyl, benzothiazolyl, benzoxazolyl, 3H-imidazo[4,5-b]pyridinyl, 1H-pyrrolo[2,3-b]pyridinyl and the like.
The term “heterocyclyl,” unless otherwise specified, refers to a non-aromatic monocyclic or bicyclic cycloalkyl group having 5 to 10 atoms wherein 1 to 4 carbon atoms in a ring are replaced by heteroatoms selected from O, S or N, and optionally are benzofused or fused heteroaryl having 5-6 ring members and/or optionally are substituted, wherein the substituents are selected from halogen (e.g., F, Cl, Br, I), hydroxy, alkyl, alkenyl, alkynyl, cycloalkyl, acyl, optionally substituted aryl, alkoxy, alkaryl, cyano, nitro, oxo, carboxy, optionally substituted heterocyclyl, optionally substituted heterocyclylalkyl, optionally substituted heteroaryl, —O—C(═O)Rλ, —O—C(═O)λ, —C(═O)NRλRπ, SOmRψ, —O—C(═O)NRλRπ, —NHC(═O)NRλRπ, —NRλRπ, mercapto, haloalkyl, thioalkyl, —COORψ, —COONHRλ, —CORλ, —NHSO2R2, or SO2NHRλ (wherein m, Rψ, Rα, and Rπ are as defined earlier) or guanidine. Heterocyclyl can optionally include rings having one or more double bonds. Such ring systems can be mono-, bi- or tricyclic. Carbonyl or sulfonyl group can replace carbon atom(s) of heterocyclyl. Unless otherwise constrained by the definition, the substituents are attached to the ring atom, i.e., carbon or heteroatom in the ring. Also, unless otherwise constrained by the definition, the heterocyclyl ring optionally may contain one or more olefinic bond(s). Examples of heterocyclyl groups include oxazolidinyl, tetrahydrofuranyl, dihydrofuranyl, benzoxazinyl, benzthiazinyl, carboxyl, phenoxazinyl, phenothiazinyl, dihydropyridinyl, dihydroisoxazolyl, dihydrobenzofuryl, azabicyclohexyl, thiazolidinyl, dihydroindolyl, pyridinyl, isoindole 1,3-dione, piperidinyl, tetrahydropyranyl, piperazinyl, isoquinolinyl, or piperazinyl and the like.
“Heteroarylalkyl” refers to heteroaryl (wherein heteroaryl is same as defined earlier) linked through alkyl (wherein alkyl is the same as defined above) portion and the said alkyl portion contains carbon atoms from 1-6.
“Heterocyclylalkyl” refers to heterocyclyl (wherein heterocyclyl is same as defined earlier) linked through alkyl (wherein alkyl is the same as defined above) portion and the said alkyl portion contains carbon atoms from 1-6.
“Acyl” refers to C(═O)R″ wherein R″ is selected from the group hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, aralkyl, heteroaryl, heterocyclyl, heteroarylalkyl or heterocyclylalkyl.
“Thiocarbonyl” refers to C(═S)H.
“Substituted thiocarbonyl” refers to —C(═S)R″ wherein R″ is selected is the same as defined earlier.
The term “leaving group” generally refers to groups that exhibit the desirable properties of being labile under the defined synthetic conditions and also, of being easily separated from synthetic products under defined conditions. Examples of such leaving groups includes but not limited to halogen (F, Cl, Br, I), triflates, tosylate, mesylates, alkoxy, thioalkoxy, hydroxy radicals and the like.
The term “Protecting Groups” is used herein to refer to known moieties, which have the desirable property of preventing specific chemical reaction at a site on the molecule undergoing chemical modification intended to be left unaffected by the particular chemical modification. Also the term protecting group, unless or other specified may be used with groups such as hydroxy, amino, carboxy and example of such groups are found in T. W. Greene and P. G. M. Wuts, “Protective Groups in Organic Synthesis”, 2nd Edn. John Wiley and Sons, New York, N.Y., which is incorporated herein by reference. The species of the carboxylic protecting groups, amino protecting groups or hydroxy protecting group employed is not so critical so long as the derivatised moiety/moieties is/are stable to conditions of subsequent reactions and can be removed at the appropriate point without disrupting the remainder of the molecule.
The term “pharmaceutically acceptable salts” refers to derivatives of compounds that can be modified by forming their corresponding acid or base salts. Pharmaceutically acceptable salts may also be formed by complete derivatization of the amine moiety e.g. quaternary ammonium salts.
In accordance with a second aspect, there is provided a method for treatment or prophylaxis of an animal or a human suffering from a disease or disorder of the respiratory, urinary and gastrointestinal systems, wherein the disease or disorder is mediated through muscarinic receptors. The method includes administration of at least one compound having the structure of Formula I.
In accordance with a third aspect, there is provided a method for treatment or prophylaxis of an animal or a human suffering from a disease or disorder associated with muscarinic receptors, comprising administering to a patient in need thereof, an effective amount of a muscarinic receptor antagonist compound as described above.
In accordance with a fourth aspect, there is provided a method for treatment or prophylaxis of an animal or a human suffering from a disease or disorder of the respiratory system such as bronchial asthma, chronic obstructive pulmonary disorders (COPD), pulmonary fibrosis, and the like; urinary system which induce such urinary disorders as urinary incontinence, lower urinary tract symptoms (LUTS), etc.; and gastrointestinal system such as irritable bowel syndrome, obesity, diabetes and gastrointestinal hyperkinesis with compounds as described above, wherein the disease or disorder is associated with muscarinic receptors.
In accordance with a fifth aspect, there are provided processes for preparing the compounds as described above.
The compounds described herein exhibit significant potency in terms of their activities, as determined by in vitro receptor binding and functional assays and in vivo experiments using anaesthetized rabbits. The compounds that were found active in vitro were tested in vivo. The compounds are potent muscarinic receptor antagonists with high affinity towards M1 and M3 receptors rather than towards M2 and/or M5 receptors. Therefore, pharmaceutical compositions for the possible treatment for the disease or disorders associated with muscarinic receptors are provided. In addition, the compounds can be administered orally or parenterally.
The compounds disclosed herein may be prepared, for example, by methods represented by the reaction sequences, for example, as generally shown in Scheme I:
The compounds of Formula IV can be prepared by following the procedure as depicted in Scheme I wherein the reaction comprises reacting a compound of Formula II (wherein R1, R2 and R3 are the same as defined earlier) with a compound of Formula III (wherein n is an integer from 1-6 and Y is —OH, —O-mesyl, —O-tosyl, —O-triflyl, —NH2. HCl or —NHR. HCl wherein R is alkyl, alkenyl, alkenyl, alkynyl or aryl, and R1′ is selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, cycloalkyl, aryl, heteroaryl, heterocyclyl, heterocyclylalkyl or heteroarylalkyl and is always a substitutent on the carbon atoms of imidazolyl ring) to give a compound of Formula IV (wherein X is selected from oxygen, —NH, —NR (wherein R is alkyl, alkenyl, alkenyl, alkynyl or aryl), sulphur or no atom). The compound of Formula IV can be further quaternized with a compound of Formula Q-Z (wherein Q can be selected from alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, heteroaryl, aralkyl, heteroarylalkyl or heterocyclylalkyl and Z is an anion disclosed in International Journal of Pharmaceutics, 33, (1986), 202 for example, but not limited to, acetate, tartarate, chloride, bromide, iodide, sulphate, phosphate, nitrate, carbonate, fumarate, glutamate, citrate, methanesulphonate, toluenesulphonate, benzenesulphonate, maleate or succinate) to give a compound of Formula IVa.
The coupling of a compound of Formula II with a compound of Formula III (when Y is —NH. HCl or —NHR. HCl) can be carried out in an organic solvent (for example, dimethylformamide, chloroform, tetrahydrofuran, diethyl ether or dioxane) in the presence of a base (for example, N-methylmorpholine, triethylamine, diisopropylethylamine or pyridine) with a condensing agent (for example, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC.HCl) or dicyclohexylcarbodiimide (DCC)).
The coupling of a compound of Formula II with a compound of Formula III (when Y is —OH or —SH) can be carried out in an organic solvent, for example, tetrahydrofuran, dimethylformamide, diethyl ether or dioxane in the presence of a coupling agent, for example, carbonyldiimidazole 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC.HCl) or dicyclohexylcarbodiimide (DCC).
Alternatively, coupling of a compound of Formula II with a compound of Formula III (when Y is —OH or —SH) can be carried out in an organic solvent (for example, toluene, heptane or xylene) in the presence of a base (for example, sodium hydride or sodium methoxide) to give a compound of Formula IV.
The coupling of a compound of Formula II with a compound of Formula III (when Y is —O-mesyl, —O-tosyl or —O-triflyl) can be carried out in an organic solvent (for example, toluene, heptane or xylene) in the presence of a base (for example, 1,8-diazabicyclo[5.4.0]undecen-7-ene (DBU) or 1,4-diazabicyclo[2.2.2]octane) to give a compound of Formula IV.
The quaternization of a compound of Formula IV to give a compound of Formula IVa can be carried out by reacting the compound of Formula IV with a compound of Formula Q-Z in an optional organic solvent selected from acetonitrile, dichloromethane, dichloroethane, carbon tetrachloride, chloroform, toluene, benzene, DMF, DMSO.
The following illustrative compounds maybe prepared for example, by Scheme I:
In the above schemes, where specific bases, condensing agents, protecting groups, deprotecting agents, solvents, catalysts, temperatures, etc. are mentioned, it is to be understood that other bases, condensing agents, protecting groups, deprotecting agents, solvents, catalysts, temperatures, etc. known to those skilled in the art may be used. Similarly, the reaction temperature and duration may be adjusted according to the desired needs.
Suitable salts of the compounds represented by the Formula I were prepared so as to solubilize the compound in aqueous medium for biological evaluations, as well as to be compatible with various dosage formulations and also to aid in the bioavailability of the compounds. Examples of such salts include pharmacologically acceptable salts such as inorganic acid salts (for example, hydrochloride, hydrobromide, sulphate, nitrate and phosphate), organic acid salts (for example, acetate, tartarate, citrate, fumarate, maleate, tolounesulphonate and methanesulphonate). When carboxyl groups are included in the Formula I as substituents, they may be present in the form of an alkaline or alkali metal salt (for example, sodium, potassium, calcium, magnesium, and the like). These salts may be prepared by various techniques, such as treating the compound with an equivalent amount of inorganic or organic, acid or base in a suitable solvent.
The compounds described herein can be produced and formulated as their enantiomers, diastereomers, N-oxides, polymorphs, solvates and pharmaceutically acceptable salts, as well as metabolites having the same type of activity. Pharmaceutical compositions comprising the molecules of Formula I or metabolites, enantiomers, diastereomers, N-oxides, polymorphs, solvates or pharmaceutically acceptable salts thereof, in combination with pharmaceutically acceptable carrier and optionally included excipient can also be produced.
Where desired, the compounds of Formula I and/or their pharmaceutically acceptable salts, pharmaceutically acceptable solvates, stereoisomers, tautomers, racemates, prodrugs, metabolites, polymorphs or N-oxides may be advantageously used in combination with one or more other therapeutic agents. Examples of other therapeutic agents, which may be used in combination with compounds of Formula I of this invention and/or their pharmaceutically acceptable salts, pharmaceutically acceptable solvates, stereoisomers, tautomers, racemates, prodrugs, metabolites, polymorphs or N-oxides include but are not limited to, corticosteroids, beta agonists, leukotriene antagonists, 5-lipoxygenase inhibitors, anti-histamines, antitussives, dopamine receptor antagonists, chemokine inhibitors, p38 MAP Kinase inhibitors, and PDE-IV inhibitors.
The compositions can be administered by inhalation.
Compositions for inhalation or insufflation include solutions and suspensions in pharmaceutically acceptable, aqueous or organic solvents, or mixtures thereof, and powders. The liquid or solid compositions may contain suitable pharmaceutically acceptable excipients. The compositions can be administered by the nasal respiratory route for local or systemic effect. Compositions can be nebulized by use of inert gases. Nebulized solutions may be breathed directly from the nebulizing device or the nebulizing device can be attached to a face mask's tent, or intermittent positive pressure breathing machine. Solution, suspension, or powder compositions can be administered nasally from devices, which deliver the formulation in an appropriate manner.
Alternatively, compositions can be administered orally, rectally, parenterally (intravenously, intramuscularly or subcutaneously), intracisternally, intravaginally, intraperitoneally or topically.
Solid dosage forms for oral administration may be presented in discrete units, for example, capsules, cachets, lozenges, tablets, pills, powders, dragees or granules, each containing a predetermined amount of the active compound. In such solid dosage forms, the active compound is admixed with at least one inert customary excipient (or carrier) such as sodium citrate or dicalcium phosphate or (a) fillers or extenders, as for example, starches, lactose, sucrose, glucose, mannitol and silicic acid, (b) binders, as for example, carboxymethylcellulose, alignates, gelatin, polyvinylpyrrolidone, sucrose and acacia, (c) humectants, as for example, glycerol, (d) disintegrating agents, as for example, agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain complex silicates and sodium carbonate, (e) solution retarders, as for example paraffin, (f) absorption accelerators, as for example, quaternary ammonium compounds, (g) wetting agents, as for example, cetyl alcohol and glycerol monostearate, (h) adsorbents, as for example, kaolin and bentonite, and (i) lubricants, as for example, talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate or mixtures thereof. In the case of capsules, tablets and pills, the dosage forms may also comprise buffering agents.
Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polyethylene glycols, and the like.
Solid dosage forms can be prepared with coatings and shells, such as enteric coatings and others well known in this art. They may contain opacifying agents, and can also be of such composition that they release the active compound or compounds in a certain part of the intestinal tract in a delayed manner Examples of embedding compositions which can be used are polymeric substances and waxes.
The active compounds can also be in micro-encapsulated form, if appropriate, with one or more of the above mentioned excipients.
Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups and elixirs. In addition to the active compounds, the liquid dosage forms may contain inert diluents commonly used in the art, such as water or other solvents, solubilizing agents and emulsifiers, as for example, ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, dimethylformamide, oils, in particular, cottonseed oil, groundnut oil, corn germ oil, olive oil, castor oil and sesame oil, glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan or mixtures of these substances, and the like.
Besides such inert diluents, the composition can also include adjuvants, for example, wetting agents, emulsifying and suspending agents, sweetening, flavoring and perfuming agents, colorants or dyes.
Suspensions, in addition to the active compounds, may contain suspending agents, as for example, ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminium metahydroxide, bentonite, agar-agar and tragacanth, or mixtures of these substances, and the like.
Dosage forms for topical administration of a compound of this invention include powder, spray, inhalant, ointment, creams, salve, jelly, lotion, paste, gel, aerosol, or oil. The active component is admixed under sterile conditions with a pharmaceutically acceptable carrier and any needed preservatives, buffers or propellants as may be required. Opthalmic formulations, eye ointments, powders and solutions are also contemplated as being within the scope of this invention.
Compositions suitable for parenteral injection may comprise pharmaceutically acceptable sterile aqueous or nonaqueous solutions, dispersions, suspensions or emulsions and sterile powders for reconstitution into sterile injectable solutions or dispersions. These preparations may contain anti-oxidants, buffers, bacteriostats and solutes, which render the compositions isotonic with the blood of the intended recipient. Aqueous and non-aqueous sterile suspensions may include suspending agents and thickening agents. The compositions may be presented in unit-dose or multi-dose containers, for example sealed ampoules and vials, and may be stored in a freeze-dried or lyophilized condition requiring only the addition of the sterile liquid carrier, for example, saline or water-for-injection immediately prior to use. Examples of suitable aqueous and nonaqueous carriers, diluents, solvents or vehicles include water, ethanol, polyols (propylene glycol, polyethylene glycol, glycerol, and the like), suitable mixtures thereof, vegetable oils (such as olive oil) and injectable organic esters such as ethyl oleate. Proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersions and by the use of surfactants.
These compositions may also contain adjuvants such as preserving, wetting, emulsifying, and dispensing agents. Prevention of the action of microorganisms can be ensured by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, and the like. It may also be desirable to include isotonic agents, for example sugars, sodium chloride and the like. Prolonged absorption of the injectable pharmaceutical form can be brought about by the use of agents delaying absorption, for example, aluminum monosterate and gelatin.
Suppositories for rectal administration of the compound of Formula I can be prepared by mixing the drug with a suitable nonirritating excipient such as cocoa butter and polyethylene glycols or a suppository wax, which are solid at ordinary temperatures but liquid at body temperature and which therefore melt in the rectum or vaginal cavity and release the drug.
If desired, and for more effective distribution, the compounds can be incorporated into slow release or targeted delivery systems such as polymer matrices, liposomes, and microspheres. They may be sterilized, for example, by filtration through a bacteria-retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved in sterile water, or some other sterile injectable medium immediately before use.
Actual dosage levels of active ingredient in the compositions of the invention and spacing of individual dosages may be varied so as to obtain an amount of active ingredient that is effective to obtain a desired therapeutic response for a particular composition and method of administration. It will be understood, however, that the specific dose level for any particular patient will depend upon a variety of factors including the compound chosen, the body weight, general health, sex, diet, route of administration, the desired duration of treatment, rates of absorption and excretion, combination with other drugs and the severity of the particular disease being treated and is ultimately at the discretion of the physician.
The pharmaceutical compositions described herein can be produced and administered in dosage units, each unit containing a certain amount of at least one compound described herein and/or at least one physiologically acceptable addition salt thereof. The dosage may be varied over extremely wide limits, as the compounds are effective at low dosage levels and relatively free of toxicity. The compounds may be administered in the low micromolar concentration, which is therapeutically effective, and the dosage may be increased as desired up to the maximum dosage tolerated by the patient.
The examples mentioned below demonstrate general synthetic procedures, as well as specific preparations of particular compounds. The examples are provided to illustrate the details of the invention and should not be constrained to limit the scope of the present invention.
Various solvents, such as acetone, methanol, pyridine, ether, tetrahydrofuran, hexanes, and dichloromethane, were dried using various drying reagents according to procedures described in the literature. IR spectra were recorded as nujol mulls or a thin neat film on a Perkin Elmer Paragon instrument, Nuclear Magnetic Resonance (NMR) were recorded on a Varian XL-300 MHz or Bruker 400 MHz instrument using tetramethylsilane as an internal standard.
To a solution of the 2-bromoethanol (5 g, 40 mmol) in dimethylformamide (25 ml) was added tert-butyidimethylsilyl chloride (7.29 g, 48 mmol) and imidazole (6.86 g, 100 mmol). The reaction mixture was stirred overnight followed by quenching with water and extraction with ethyl acetate. The organic layer was dried over anhydrous sodium sulphate and concentrated under reduced pressure to furnish the title compound. Yield: 8 g.
Sodium hydride (8.4 g, 210 mmol) was added slowly to dry dimethylformamide (40 ml) precooled at −10° C. under nitrogen atmosphere. To the resulting suspension was added 2-methyl imidazole (20.67 g, 252 mmol) at −10° C. and the reaction mixture was allowed to warm to room temperature. The reaction mixture was stirred for 1 hour at room temperature followed by cooling to 0° C. To the mixture was added solution of the compound obtained from step a above (20 g, 84 mmol) in dimethylformamide (10 ml) and stirred at room temperature for overnight. The mixture was quenched with aqueous ammonium chloride solution and extracted with dichloromethane. The dichloromethane layer was dried over anhydrous sodium sulphate and concentrated under reduced pressure to furnish the title compound. Yield: 12.5 g.
To a compound obtained from step b above (12.5 g, 55.6 mmol) was added a solution of ethanolic hydrochloric acid solution (2%, 90 ml) at room temperature and stirred the mixture overnight. The reaction mixture was concentrated under reduced pressure. The residue thus obtained washed with diethyl ether to furnish the title compound. Yield: 3.9 g.
The following compounds were prepared similarly,
Hydrochloride salt of 2-(2-methyl-imidazol-1-yl)-propanol; and
Hydrochloride salt of 2-(2-methyl-imidazol-1-yl)-butanol.
To a solution of the compound obtained from step c above (4 g, 24.6 mmol) in dichloromethane (60 ml) was added triethylamine (10.27 ml, 73.8 mmol) and dimethylaminopyridine (150 mg) at 0° C. The reaction mixture was stirred until the compound obtained from step c above becomes completely soluble. The mixture was cooled down to −5° C. followed by the addition methane sulphonyl chloride (2.86 ml, 36.9 mmol) dropwise with stirring. The mixture was stirred for 3 hours at −5° C. and then at room temperature for overnight. The mixture was diluted with sodium bicarbonate solution and extracted with dichloromethane. The dichloromethane layer was dried over anhydrous sodium sulphate and concentrated under reduced pressure to furnish the title compound. Yield: 3.8 g.
1HNMR (CDCl3)=6.94 (d, 1H), 6.89-6.90 (d, 1H), 4.38-4.41 (t, 2H), 4.19-4.22 (t, 2H), 2.85 (s, 3H), 2.42 (s, 3H).
To a solution of hydrochloride salt of 2-(2-methyl-imidazol-1-yl)-propanol (1.5 g, 0.0078 mol) and 4-dimethylaminopyridine (catalytic amount) in dry dichloromethane cooled to −30° C. was added triethylamine (5.5 ml, 0.0393 mol) drop wise and allowed to warm to 20° C. The reaction mixture was again cooled to −50° C. and methanesulphonyl chloride (0.9 ml, 0.0117 mol) was added drop wise. The reaction mixture was allowed to warm to 20° C. and stirred at same temperature for 1 hour. The reaction mixture was quenched with aqueous sodium bicarbonate and extracted with dichloromethane. The combined organic layer was washed with water and brine, dried over anhydrous sodium sulphate and concentrated under reduced pressure. The residue thus obtained was purified by column chromatography using methanol:trithylamine:dichloromethane (1:2:7) as eluent to furnish the desired compound. Yield: 1.3 g.
1HNMR (CDCl3): δ 6.87-6.88 (d, 1H), 7.04 (d, 1H), 3.9 (m, 2H), 4.1 (m, 2H), 3.0 (s, 3H), 2-2.05 (m, 2H).
The following compound was prepared similarly,
Methanesulphonic acid 2-(2-methyl-imidazol-1-yl)-butyl ester.
(R)-Mandelic acid (36.8 g, 0.2419 mol), pivaldehyde (86.13 g, 0.2903 mol) and trifluoromethane sulphonic acid (0.9 ml, 0.0096 mol) were taken in n-pentane (350 ml). The reaction mixture was refluxed for 5-6 hours and water was azeotropically removed with Dean stark apparatus. The reaction mixture was concentrated under reduced pressure. The residue thus obtained was taken in ethyl acetate and washed with aqueous sodium bicarbonate solution. The organic layer was separated, washed with water and brine, dried over anhydrous sodium sulphate and concentrated under reduced pressure to furnish the title compound. Yield: 50.0 g.
To a solution of compound obtained from step a (15 gm, 0.0681 mol) in dry tetrahydrofuran (700 ml) was added hexamethylphosphoric acid (54 ml) and cooled to −78° C. and then added lithium diisopropylamine (38 ml, 0.0749 mol, 2 Molar solution in tetrahydrofuran). The reaction mixture was stirred at same temperature for 30 minutes, then added cyclohexenone (9.9 ml, 0.1022 mol). The reaction mixture was again stirred at −78° C. for 2 hours. The reaction mixture was quenched with aqueous ammonium chloride solution and extracted with ethyl acetate. The combined organic layer was washed with water and brine, dried over anhydrous sodium sulphate and concentrated under reduced pressure. The residue was purified over silica gel using ethyl acetate (2:8) to furnish the desired diastereomers.
Yield of (5R)-2-tert-butyl-5-[(1S)-3-oxocyclohexyl]-5-phenyl-1,3-dioxolan-4-one: 4.5 g
Yield of (5R)-2-tert-butyl-5-[(1R)-3-oxocyclohexyl]-5-phenyl-1,3-dioxolan-4-one: 1.4 g
1HNMR (CDCl3) of (5R)-2-tert-butyl-5-[(1R)-3-oxocyclohexyl]-5-phenyl-1,3-dioxolan-4-one: δ 7.63-7.65 (m, 2H), 7.31-7.52 (m, 3H), 5.38 (s, 1H), 1.04-2.48 (m, 9H), 0.89 (s, 9H).
1HNMR (CDCl3) of (5R)-2-tert-butyl-5-[(1S)-3-oxocyclohexyl]-5-phenyl-1,3-dioxolan-4-one: δ 7.64-7.65 (m, 2H), 7.31-7.52 (m, 3H), 5.38 (s, 1H), 1.25-2.48 (m, 9H), 0.89 (s, 9H)
To a solution of (5R)-2-tert-butyl-5-[(1R)-3-oxocyclohexyl]-5-phenyl-1,3-dioxolan-4-one (1.4 g, 0.0044 mol) in chloroform (15 ml) cooled to 0° C. was added diethylaminosulfur trifluoride (DAST) (1.8 ml, 0.0146 mol) under nitrogen atmosphere. After addition at 0° C., the reaction mixture was allowed to stir at room temperature for two days. The reaction mixture was cooled on an ice bath and slowly quenched with aqueous ammonium chloride solution. The organic layer was separated and aqueous layer was extracted twice with dichloromethane. The combined organic layer was washed with water and brine and dried over anhydrous sodium sulphate and concentrated to get crude compound. The crude compound was purified over silica using 2-5% ethyl acetate in hexane. Yield: 650 mg.
1HNMR (CDCl3): δ 7.62-7.64 (m, 2H), 7.30-7.51 (m, 3H), 5.38 (s, 1H), 1.04-2.29 (m, 9H), 0.90 (s, 9H).
Following compound was prepared similarly by using (5R)-2-tert-butyl-5-[(1S)-3-oxocyclohexyl]-5-phenyl-1,3-dioxolan-4-one in place of (5R)-2-tert-butyl-5-[(1R)-3-oxocyclohexyl]-5-phenyl-1,3-dioxolan-4-one,
To a solution of (5R)-2-tert-butyl-5-[(1R)-3,3-difluorocyclohexyl]-5-phenyl-1,3-dioxolan-4-one (330 mg, 0.0009 mol) in methanol (15 ml) cooled to 0° C. was added dropwise solution of sodium hydroxide (5 ml, 3 N, 10 eq., 0.009 mol). The reaction mixture was stirred at 0° C. for 30 minutes and then stirred at room temperature for overnight. The reaction mixture was concentrated under reduced pressure. The residue was taken in water and washed with dichloromethane. The aqueous layer was acidified with concentrated HCl and then extracted with ethyl acetate. The combined organic layer was washed with water and brine and dried over anhydrous sodium sulphate and concentrated under reduced pressure to furnish the desired compound. Yield: 240 mg.
1HNMR (CDCl3) δ=7.62-7.65 (m, 2H), 7.28-7.40 (m, 3H), 2.59-2.62 (m, 1H), 1.11-2.06 (m, 8H).
The following compound was prepared similarly,
To a solution of the compound (2R)-[(1R)-3,3-difluorocyclohexyl](hydroxy)phenylacetic acid (300 mg, 1.11 mmoles), methanesulphonic acid 2-(2-methyl-imidazol-1-yl)-ethyl ester (226 mg, 1.11 mmoles) and toluene (20 ml) was added 1,8-diazabicyclo[5.4.0]undecen-7-ene (338 mg, 2.22 mmoles) and stirred the mixture overnight under reflux for overnight. The organic solvent was evaporated under reduced pressure and the residue thus obtained was purified by column chromatography. Yield: 280 mg.
The following compounds were prepared similarly,
To the solution of the Compound No. 126 (30 mg) in acetonitrile (1.5 ml), 4-bromobenzylbromide (excess) was added and the reaction mixture was stirred at 55° C. overnight and subsequently at room temperature for further 24 hours. The reaction mixture was then concentrated under reduced pressure. The residue was washed with diethyl ether several times and dried under vacuum to furnish the desired compound.
Yield: 20 mg.
Mass Spectrum (M/z): 547 (M+)
The following analogues were prepared similarly by using appropriate alkyl halide, varying the temperature and time and in the presence of optional co-solvent (such as dichloromethane or chloroform), as applicable in each case.
The affinity of test compounds for M1, M2 and M3 muscarinic receptor subtypes was determined by [3H]-N-methylscopolamine binding studies using rat heart and submandibular gland respectively as described by Moriya et al., (Life Sci., 64, (25): (1999), 2351-2358) with minor modifications. In competition binding studies, specific binding of [3H]NMS was also determined using membranes from Chinese hamster ovary (CHO) cells expressing cloned human M1, M2, M3, M4 and M5 receptors. Selectivities were calculated from the Ki values obtained on these human cloned membranes.
Membrane preparation: Submandibular glands and heart were isolated and placed in ice-cold homogenizing buffer (HEPES 20 mM, 10 mM EDTA, pH 7.4) immediately after sacrifice. The tissues were homogenized in 10 volumes of homogenizing buffer and the homogenate was filtered through two layers of wet gauze and filtrate was centrifuged at 500 g for 10 minutes at 4° C. The supernatant was subsequently centrifuged at 40,000 g for 20 minutes at 4° C. The pellet thus obtained was resuspended in assay buffer (HEPES 20 mM, EDTA 5 mM, pH 7.4) and were stored at −70° C. until the time of assay.
Ligand binding assay: The compounds were dissolved and diluted in DMSO. The membrane homogenates (150-250 μg protein) were incubated in 250 μl of assay volume (HEPES 20 mM, pH 7.4) at 24-25° C. for 3 hours. Non-specific binding was determined in the presence of 1 μM atropine. The incubation was terminated by vacuum filtration over GF/B fiber filters (Wallac). The filters were then washed with ice-cold 50 mM Tris HCl buffer (pH 7.4). The filter mats were dried and bound radioactivity retained on filters was counted. The IC50 & Kd were estimated by using the non-linear curve fitting program using G Pad Prism software. The value of inhibition constant Ki was calculated from competitive binding studies by using Cheng & Prusoff equation (Biochem. Pharmacol., 22, (1973), 3099-3108) Ki═IC50/(1+L/Kd), where L is the concentration of [3H]NMS used in the particular experiment. pKi is −log [Ki].
The Ki at M2 receptor is in the range of from about 1.7 nM to about 1000 nM, for example, from about 5.0 nM to about 1000 nM, or for example, from about 10 nm to about 1000 nM, or for example, from about 30 nM to about 1000 nM.
The Ki at M3 receptor is in the range of from about 0.3 nM to about 370 nM, for example, from about 0.3 nM to about 40 nM, or from about 0.3 nM to about 1.0 nM, or from about 0.3 nM to about 3.0 nM, or from about 0.3 nM to about 1.5 nM. Selectivity of compounds for M3 receptors as compared to M2 receptors ranged from about 1.5 to about 90, or from about 4 to about 90, or from about 12 to about 90. Compound Nos. 61, 94 and 101-106 were not selective for M3 over M2 receptors, as expressed by Ki(M2)/Ki(M3).
Animals are euthanized by overdose of thiopentone and whole bladder is isolated and removed rapidly and placed in ice cold Tyrode buffer with the following composition (mMol/L) NaCl 137; KCl 2.7; CaCl2 1.8; MgCl2 0.1; NaHCO3 11.9; NaH2PO4 0.4; Glucose 5.55 and continuously gassed with 95% O2 and 5% CO2.
The bladder is cut into longitudinal strips (3 mm wide and 5-6 mm long) and mounted in 10 ml organ baths at 30° C., with one end connected to the base of the tissue holder and the other end connected through a force displacement transducer. Each tissue is maintained at a constant basal tension of 1 g and allowed to equilibrate for 1½ hour during which the Tyrode buffer is changed every 15-20 minutes. At the end of equilibration period the stabilization of the tissue contractile response is assessed with 1 μmol/L of carbachol till a reproducible response is obtained. Subsequently a cumulative concentration response curve to carbachol (10−9 mol/L to 3×10−4 mol/L) is obtained. After several washes, once the baseline is achieved, cumulative concentration response curve is obtained in presence of NCE (NCE added 20 minutes prior to the second cumulative response curve.
The contractile results are expressed as % of control E max. ED50 values are calculated by fitting a non-linear regression curve (Graph Pad Prism). pKb values are calculated by the formula pKb=−log [(molar concentration of antagonist/(dose ratio−1))]
where,
dose ratio=ED50 in the presence of antagonist/ED50 in the absence of antagonist.
The Guinea Pig (400-600 gm) was procured and trachea was removed under anesthesia (sodium pentobarbital, 300 mg/kg i.p) and was immediately kept it in ice-cold Krebs Henseleit buffer. Indomethacin (10 μM) was present throughout the KH buffer to prevent the formation of bronchoactive prostanoids.
The tissue of adherent fascia was cleaned and was cut into strips of equal size (with approximately 4-5 tracheal rings in each strip). The epithelium was removed by careful rubbing, minimizing damage to the smooth muscle. Trachea was opened along the mid-dorsal surface with the smooth muscle band intact and made a series of transverse cuts from alternate sides so that they do not transect the preparation completely. Opposite ends of the cut rings were tied with the help of a thread. The tissue was mounted in isolated tissue baths containing 10 ml Krebs Henseleit buffer maintained at 37° C. and bubbled with carbogen, at a basal tension of 1 gm. The buffer was changed 4-5 times for about an hour. The tissue was equilibrated for 1 hour for stabilization. After 1 hour, the tissue was challenged with 1 μM carbachol. This was repeated after every 2-3 washes till two similar consecutive responses were obtained. At the end of stabilization, the tissue was washed for 30 minutes followed by incubation with suboptimal dose of MRA/Vehicle for 20 minutes prior to contraction of the tissues with 1 μM carbachol. The contractile response of tissues was recorded either on Powerlab data acquisition system or on Grass polygraph (Model 7). The relaxation was expressed as percentage of maximum carbachol response. The data was expressed as mean±s.e. mean for n observations. The EC50 was calculated as the concentration producing 50% of the maximum relaxation to 1 μM carbachol. The percent relaxation was compared between the treated and control tissues using non-parametric unpaired t-test. A p value of <0.05 was considered to be statistically significant.
The tested compounds (Nos. 5, 6, 9, 13, 17, 19, 21-23, 28-31, 33, 37, 51, 85, and 95) exhibited a pKb in the range of about 8.5 to about 10.
In-Vitro Functional Assay to Evaluate Efficacy of “MRA” in Combination with “PDE-IV Inhibitors”
The Guinea Pig (400-600 gm) is procured and the trachea is removed under anesthesia (sodium pentobarbital, 300 mg/kg i.p.) and is immediately kept in ice-cold Krebs Henseleit buffer. Indomethacin (10 μM) is present throughout the KH buffer to prevent the formation of bronchoactive prostanoids.
The tissue of the adherent fascia is cleaned and is cut into strips of equal size (with approximately 4-5 tracheal rings in each strip). The epithelium is removed by careful rubbing, minimizing damage to the smooth muscle. The trachea is opened along the mid-dorsal surface with the smooth muscle band intact and make a series of transverse cuts from alternate sides so that they do not transect the preparation completely. The opposite ends of the cut rings are tied with the help of a thread. The tissue is mounted in isolated tissue baths containing 10 ml Krebs Henseleit buffer maintained at 37° C. and bubbled with carbogen, at a basal tension of 1 gm. The buffer is changed 4-5 times for about an hour. The tissue is equilibrated for 1 hour for stabilization. After 1 hour, the tissue is challenged with 1 μM carbachol. This is repeated after every 2-3 washes till two similar consecutive responses are obtained. At the end of stabilization, the tissues are washed for 30 minutes followed by incubation with suboptimal dose of MRA/Vehicle for 20 minutes prior to contraction of the tissues with 1 μM carbachol and subsequently assess the relaxant activity of the PDE-IV inhibitor [10−9 M to 10−4 M] on the stabilized developed tension/response. The contractile response of tissues is recorded either on Powerlab data acquisition system or on Grass polygraph (Model 7). The relaxation is expressed as percentage of maximum carbachol response. The data is expressed as mean±s.e. mean for n observations. The EC50 is calculated as the concentration producing 50% of the maximum relaxation to 1 μM carbachol. The percent relaxation is compared between the treated and control tissues using non-parametric unpaired t-test. A p value of <0.05 is considered to be statistically significant.
Male Guinea pigs are anesthetized with urethane (1.5 g/kg, i.p.). Trachea is cannulated along with jugular vein (for carbachol challenge) and animals are placed in the Plethysmograph-Box (PLY 3114 model; Buxco Electronics, Sharon, USA.). Respiratory parameters are recorded using Pulmonary Mechanics Analyzer, Biosystems XA software (Buxco Electronics, USA), which calculated lung resistance (RL) on a breath-by-breath basis. Bronchoconstriction is induced by injections of carbachol (10 μg/kg) delivered into the jugular vein. Increase in RL over a period of 5 minutes post carbachol challenge is recorded in presence or absence of MRA or vehicle at 2 hours and 12 hours post treatment and expressed as % increase in RL from basal.
In-Vivo Assay to Evaluate Efficacy of MRA in Combination with PDE-IV Inhibitors
MRA (1 μg/kg to 1 mg/kg) and PDE-IV inhibitor (1 μg/kg to 1 mg/kg) are instilled intratracheally under anesthesia either alone or in combination.
Male wistar rats weighing 200±20 gm are used in the study. Rats have free access to food and water. On the day of experiment, animals are exposed to lipopolysaccharide (LPS, 100 μg/ml) for 40 minutes. One group of vehicle treated rats is exposed to phosphate buffered saline (PBS) for 40 minutes. Two hours after LPS/PBS exposure, animals are placed inside a whole body plethysmograph (Buxco Electronics, USA) and exposed to PBS or increasing acetylcholine (1, 6, 12, 24, 48 and 96 mg/ml) aerosol until Penh values (index of airway resistance) of rats attained 2 times the value (PC-100) seen with PBS alone. The respiratory parameters are recorded online using Biosystem XA software, (Buxco Electronics, USA). Penh, at any chosen dose of acetylcholine is, expressed as percent of PBS response and the using a nonlinear regression analysis PC100 (2 folds of PBS value) values are computed. Percent inhibition is computed using the following formula.
PC100LPS=PC100 in untreated LPS challenged group
PC100TEST=PC100 in group treated with a given dose of test compound PC100PBS=PC100 in group challenged with PBS
Immediately after the airway hyperreactivity response is recorded, animals are sacrificed and bronchoalveolar lavage (BAL) is performed. Collected lavage fluid is centrifuged at 3000 rpm for 5 minutes, at 4° C. Pellet is collected and resuspended in 1 ml HBSS. Total leukocyte count is performed in the resuspended sample. A portion of suspension is cytocentrifuged and stained with Leishmann's stain for differential leukocyte count. Total leukocyte and neutrophil counts are expressed as cell count (millions cells m1−1 of BAL). Percent inhibition is computed using the following formula.
NCLPS=Percentage of neutrophil in untreated LPS challenged group
NCTEST=Percentage of neutrophil in group treated with a given dose of test compound
NCCON=Percentage of neutrophil in group not challenged with LPS
The percent inhibition data is used to compute ED50 vales using Graph Pad Prism software (Graphpad Software Inc., USA).
In-Vivo Assay to Evaluate Efficacy of MRA in Combination with Corticosteroids
Guinea pigs are sensitised on days 0, 7 and 14 with 50-μg ovalbumin and 10 mg aluminium hydroxide injected intraperitoneally. On days 19 and 20 guinea pigs are exposed to 0.1% w v−1 ovalbumin or PBS for 10 minutes, and with 1% ovalbumin for 30 minutes on day 21. Guinea pigs are treated with test compound (0.1, 0.3 and 1 mg kg−1) or standard 1 mg kg−1 or vehicle once daily from day 19 and continued for 4 days. Ovalbumin/PBS challenge is performed 2 hours after different drug treatment.
EOSOVA=Percentage of eosinophil in untreated ovalbumin challenged group
EOSTEST=Percentage of eosinophil in group treated with a given dose of test compound
EOSCON=Percentage of eosinophil in group not challenged with ovalbumin.
In-Vivo Assay to Evaluate Efficacy of “MRA” in Combination with p38 MAP Kinase Inhibitors
Lipopolysaccharide (LPS) induced airway hyperreactivity (AHR) and neutrophilia:
MRA (1 μg/kg to 1 mg/kg) and p38 MAP kinase inhibitor (1 μg/kg to 1 mg/kg) are instilled intratracheally under anesthesia either alone or in combination.
Male wistar rats weighing 200±20 gm are used in the study. Rats have free access to food and water. On the day of experiment, animals are exposed to lipopolysaccharide (LPS, 100 μg/ml) for 40 minutes. One group of vehicle treated rats is exposed to phosphate buffered saline (PBS) for 40 minutes. Two hours after LPS/PBS exposure, animals are placed inside a whole body plethysmograph (Buxco Electronics, USA) and exposed to PBS or increasing acetylcholine (1, 6, 12, 24, 48 and 96 mg/ml) aerosol until Penh values (index of airway resistance) of rats attained 2 times the value (PC-100) seen with PBS alone. The respiratory parameters are recorded online using Biosystem XA software, (Buxco Electronics, USA). Penh, at any chosen dose of acetylcholine is, expressed as percent of PBS response and the using a nonlinear regression analysis PC100 (2 folds of PBS value) values are computed. Percent inhibition is computed using the following formula.
PC100LPS=PC100 in untreated LPS challenged group
PC100TEST=PC100 in group treated with a given dose of test compound
PC100PBS=PC100 in group challenged with PBS
Immediately after the airway hyperreactivity response is recorded, animals are sacrificed and bronchoalveolar lavage (BAL) is performed. Collected lavage fluid is centrifuged at 3000 rpm for 5 minutes, at 4° C. Pellet is collected and resuspended in 1 ml HBSS. Total leukocyte count is performed in the resuspended sample. A portion of suspension is cytocentrifuged and stained with Leishmann's stain for differential leukocyte count. Total leukocyte and neutrophil counts are expressed as cell count (millions cells ml−1 of BAL). Percent inhibition is computed using the following formula.
NCLPS=Percentage of neutrophil in untreated LPS challenged group
NCTEST=Percentage of neutrophil in group treated with a given dose of test compound
NCCON=Percentage of neutrophil in group not challenged with LPS
The percent inhibition data is used to compute ED50 vales using Graph Pad Prism software (Graphpad Software Inc., USA).
In-Vivo Assay to Evaluate Efficacy of “MRA” in Combination with β2-Agonists
MRA (1 μg/kg to 1 mg/kg) and long acting β2 agonist are instilled intratracheally under anesthesia either alone or in combination.
Wistar rats (250-350 gm) or balb/C mice (20-30 gm) are placed in body box of a whole body plethysmograph (Buxco Electronics, USA) to induce bronchoconstriction. Animals are allowed to acclimatise in the body box and are given successive challenges, each of 2 minutes duration, with PBS (vehicle for acetylcholine) or acetylcholine (i.e. 24, 48, 96, 144, 384, and 768 mg/ml). The respiratory parameters are recorded online using Biosystem XA software, (Buxco Electronics, USA) for 3 minutes. A gap of 2 minutes is allowed for the animals to recover and then challenged with the next higher dose of acetylcholine (ACh). This step is repeated until Penh of rats attained 2 times the value (PC-100) seen with PBS challenge. Following PBS/ACh challenge, Penh values (index of airway resistance) in each rat/mice is obtained in the presence of PBS and different doses of ACh. Penh, at any chosen dose of ACh is, expressed as percent of PBS response. The Penh values thus calculated are fed into Graph Pad Prism software (Graphpad Software Inc., USA) and using a nonlinear regression analysis PC100 (2 folds of PBS value) values are computed. % inhibition is computed using the following formula.
PC100CON=PC100 in vehicle treated group
PC100TEST=PC100 in group treated with a given dose of test compound
768=is the maximum amount of acetylcholine used.
While the present invention has been described in terms of its specific embodiments, certain modification and equivalents will be apparent to those skilled in the art and are intended.
| Number | Date | Country | Kind |
|---|---|---|---|
| 449/DEL/2007 | Feb 2007 | IN | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/IB08/50706 | 2/27/2008 | WO | 00 | 1/20/2010 |
