Toward the development of chemoprevention agents (III): synthesis and anti-inflammatory activities of a new class of 5-glycylamino-2-substituted-phenyl-1,3-dioxacycloalkanes

A new series of 5-glycylamino-2-substituted-phenyl-1,3-dioxacycloalkanes were designed and synthesized. The anti-inflammatory activities of these compounds were tested using the xylene-induced mouse ear edema model. Sixteen of these new compounds exhibited comparable or better anti-inflammatory activities than aspirin suggesting that they can be further developed as potential anti-inflammatory drug leads. In addition, treatment with these anti-inflammatory agents did not prolong tail bleeding time in mice. The structure/activity relationships were also analyzed among these compounds. Considering their good efficacy and safety profiles, some 5-glycylamino-2-substituted-phenyl-1,3-dioxacycloalkanes are worthy to be explored further in assessing the possible link between anti-inflammation and cancer prevention.     

Stereoselective synthesis and anti-inflammatory activities of 6- and 7-membered dioxacycloalkanes

A class of 5-trifluoroacetylamino-1,3-dioxacycloalkanes, 5-benzoylamino-1,3-dioxacycloalkanes, and 5-amino-1,3-dioxacycloalkane compounds were stereoselectively synthesized as potential anti-inflammatory drug candidates. The anti-inflammatory activities of these compounds were tested using the xylene-induced mouse ear edema model, from which multiple compounds possessing anti-inflammatory properties which surpass aspirin were identified; these compounds were then compared to establish structure-activity relationships.     

Synthesis and biological evaluation of some 5-arylidene-2-(1,3-thiazol-2-ylimino)-1,3-thiazolidin-4-ones as dual anti-inflammatory/antimicrobial agents

As a part of our ongoing studies in developing new derivatives as dual antimicrobial/anti-inflammatory agents we describe the synthesis of novel 5-arylidene-2-(1,3-thiazol-2-ylimino)-1,3-thiazolidin-4-ones. All newly synthesized compounds were tested for their anti-inflammatory activity using carrageenan mouse paw edema bioassay. Their COX-1/LOX inhibitory activities were also determined. Moreover, all compounds were evaluated for their antimicrobial and antifungal activities against a panel of Gram positive, Gram negative bacteria and moulds. All tested compounds exhibited better antimicrobial activity than commercial drugs, bifonazole, ketoconazole, ampicillin and streptomycin.     

Toward the development of chemoprevention agents. Part 1: Design, synthesis, and anti-inflammatory activities of a new class of 2,5-disubstituted-dioxacycloalkanes

A new class of 2,5-disubstituted-dioxacycloalkanes were designed and synthesized via stereoselective synthetic method as cancer chemoprevention agents. The anti-inflammatory activities of these compounds were tested using the xylene-induced mouse ear edema model. Some of these compounds exhibited comparable or better anti-inflammatory activities than that of aspirin suggesting that they can be further developed as potential anti-inflammatory drug lead compounds. In addition, treatment of these anti-inflammatory agents did not prolong tail bleeding time in mice. The structure/activity relationships were also analyzed among these compounds.     

A facile synthesis,anti-inflammatory and analgesic activity of isoxazolyl-2,3-dihydrospiro[benzo[f]isoindole-1,3′-indoline]-2′,4,9-triones

A new series of isoxazolyl-2,3-dihydrospiro[benzo[f]isoindole-1,3′-indoline]-2′,4,9-triones (14) were synthesized by reaction of 4-amino-3-methyl-5-styrylisoxazole 10 with chloroacetic acid followed by a three component reaction with substituted isatins 12 and 1,4-naphthoquinone 13 using Ceric ammonium nitrate (CAN) catalyst under aerial oxidation condition. Structures of these compounds were established on the basis of IR, ¹H NMR, ¹³C NMR and mass spectral data. The title compounds 14a–j were evaluated for their anti-inflammatory and analgesic activity. Compounds 14d, 14e and 14f exhibited potent anti-inflammatory and analgesic activity as that of standard drugs.     

Analogue-based design, synthesis and molecular docking analysis of 2,3-diaryl quinazolinones as non-ulcerogenic anti-inflammatory agents

In our effort to identify potent gastric sparing anti-inflammatory agents, a series of methyl sulfanyl/methyl sulfonyl substituted 2,3-diaryl quinazolinones were designed by analogue-based design strategy and synthesized for biological evaluation. Subsequently, the compounds were evaluated for both cyclooxygenase inhibitions by ovine COX assay and carrageenan-induced rat paw edema assay. All the methyl sulfonyl substituted quinazolinones were exhibited promising anti-inflammatory activity. In particular, 6-bromo-3-(4-methanesulfonyl-phenyl)-2-phenyl-3H-quinazolin-4-one, 7-chloro-3-(4-methanesulfonyl-phenyl)-2-phenyl-3H-quinazolin-4-one, 3-(4-methanesulfonyl-phenyl)-2-(4-methoxy-phenyl)-3H-quinazolin-4-one and 6-bromo-3-(4-methanesulfonyl-phenyl)-2-(4-methoxy-phenyl)-3H-quinazolin-4-one emerged as the most active compounds in the series. The results of ulcerogenic activity assay suggest that these compounds are gastric safe compared to indomethacin. The molecular docking analysis was performed to understand the binding interactions of these compounds to COX-2 enzyme. The results from the present investigation suggests that 2,3-diaryl quinazolinones as a promising template for the design of new gastric safe anti-inflammatory agents, which can be further explored for potential anti-inflammatory activity.     

Synthesis,molecular docking and biological evaluation of some newer 2-substituted-4-(benzo[d][1,3]dioxol-5-yl)-6-phenylpyridazin-3(2H)-ones as potential anti-inflammatory and analgesic agents

A new series of 2-substituted-4-(benzo[d][1,3]dioxol-5-yl)-6-phenylpyridazin-3(2H)-one derivatives has been synthesized and studied. The in vivo anti-inflammatory and analgesic activities of the synthesized compounds were evaluated using carrageen rat paw edema model and acetic acid induced writhing model, respectively. Side effect profile of the newly synthesized pyridazinones was assessed by gastric ulcerogenic and anti-platelet activity. The compounds were further evaluated for their inhibitory activity against cyclooxygenase enzyme (COX-1/COX-2) by in vitro colorimetric COX (ovine) inhibitor screening assay method. The p-flourophenylpiperazine substituted analogue 14 exhibited most potent anti-inflammatory and analgesic activities with lower ulcer index and extremely good selectivity towards COX-2 versus COX-1 enzyme with a selectivity index of 10. Molecular docking studies showed appreciable binding of new pyridazinone analogues with the amino acids present at the active site of hCOX-2 enzyme.     

Synthesis and pharmacological evaluation of a novel series of 3-aryl-2-(2-substituted-4-methylthiazole-5-yl)thiazolidin-4-one as possible anti-inflammatory and antimicrobial agents

A new series of 3-aryl-2-(2-aryl/benzyl-4-methylthiazole-5-yl)thiazolidin-4-one was synthesized by condensation of 2-aryl/benzyl-4-methylthiazole-5-carbaldehyde, aromatic amines and thioglycolic acid in toluene. All the synthesized compounds are characterized by IR, NMR and elemental or mass analysis. Sixteen out of the newly synthesized compounds were screened for in vivo anti-inflammatory activity using carrageenan-induced rat paw edema method. Some of the synthesized compounds exhibited good anti-inflammatory activity compared with indomethacin. The synthesized compounds were also evaluated for their in vitro antimicrobial activity. Some of the compounds showed mild antibacterial activity while most of the compounds showed good antifungal activity.     

Synthesis and biological evaluation of 2-trifluoromethyl/sulfonamido-5,6-diaryl substituted imidazo[2,1-b]-1,3,4-thiadiazoles: a novel class of cyclooxygenase-2 inhibitors

A series of 2-trifluoromethyl/sulfonamido-5,6-diarylsubstituted imidazo[2,1-b]-1,3,4-thiadiazole derivatives 15a-j have been synthesized by the reaction of 2-amino-5-trifluoromethyl/sulfonamido-1,3,4-thiadiazoles 14a-b and appropriately substituted alpha-bromo-1,2-(p-substituted)diaryl-1-ethanones 13a-h. Structures of these compounds were established by IR, (1)H NMR, (13)C NMR, Mass, and HRMS data. The selected compounds were evaluated for their preliminary in vitro cyclooxygenase inhibitory activity against COX-2 and COX-1enzymes using colorimetric method. The compounds tested showed selective inhibitory activity toward COX-2 (80.6-49.4%) over COX-1 (30.6-8.6), amongst them compounds 15f and 15j showed appreciable COX-2 selective inhibitory activity. These compounds also exhibited significant anti-inflammatory activity (70.09-42.32%), which is comparable to that of celecoxib in the carrageenan-induced rat paw edema method.     

Design,synthesis, docking and anti-inflammatory evaluation of novel series of benzofuran based prodrugs

Several new benzofuran derivatives were synthesized, via appropriate synthetic route as anti-inflammatory agents. The anti-inflammatory activity of the prepared compounds was evaluated using carrageenan rat model. Among the synthesized compounds, some compounds showed comparable anti-inflammatory activity to nimesulide, the standard drug taken for anti-inflammatory studies. Docking study of the prepared compounds was performed for the study of interaction of molecules with the active site of COX-2. Preliminary biological studies and docking gave an interesting insight, into the validity of employing benzofuran analogues as good anti-inflammatory agent.     

In vitro and molecular docking studies of an anti-inflammatory scaffold with human peroxiredoxin 5 and tyrosine kinase receptor

A new series of 4-(3-(2-amino-3,5-dibromophenyl)-1-(4-substitutedbenzoyl)-4,5-dihydro-1H-pyrazol-5-yl)benzonitrile (4a-h) compounds were synthesized and evaluated for in-vitro anti-inflammatory activities. The spectral (IR, NMR) and elemental analyses data of the product indicated the formation of new pyrazoles 4a-h. Compound 4e exhibited potent anti-inflammatory property with 85.45 % inhibitions. This value was compared with standard diclofenac sodium. This data is explained using molecular docking analysis of receptor- ligand binding. These results demonstrated that pyrazole derivatives are potential inhibitors of Human Peroxiredoxin 5 and Tyrosine kinase receptor in the treatment of inflammation related illness.     

The evaluation and structure-activity relationships of 2-benzoylaminobenzoic esters and their analogues as anti-inflammatory and anti-platelet aggregation agents

Forty-seven 2-benzoylaminobenzoic esters were synthesized and evaluated in anti-platelet aggregation, inhibition of superoxide anion generation, and inhibition of neutrophil elastase release assays. Most 2-benzoylamino-4-chlorobenzoic acid derivatives showed selective inhibitory effects on arachidonic acid (AA)-induced platelet aggregation. Among them, compounds 6b and 7b exhibited more potent inhibitory effects (ca. 200-fold) than aspirin. Additionally, compounds 1a and 5a showed strong inhibitory effects on neutrophil superoxide generation with IC(50) values of 0.65 and 0.17 microM, respectively. However, compounds 6d and 6e exhibited dual inhibitory effects on platelet aggregation and neutrophil elastase (NE) release; therefore, these two compounds may be new leads for development as anti-inflammatory and anti-platelet aggregatory agents.     

Synthesis and anti-inflammatory activity of some novel 3-phenyl-N-[3-(4-phenylpiperazin-1yl)propyl]-1H-pyrazole-5-carboxamide derivatives

A new series of 3-phenyl-N-[3-(4-phenylpiperazin-1yl)propyl]-1H-pyrazole-5-carboxamide derivatives were synthesized and investigated their anti-inflammatory activities using carrageenan-induced rat paw edema model in vivo. All the synthesized compounds were found to be potent anti-inflammatory agents.     

Synthesis of new 5,6-dihydrobenzo[h]quinazoline 2,4-diamino substituted and antiplatelet/antiphlogistic activities evaluation

In pursuing our research on some 2,4-diamino-benzopyranopyrimidines and 2-amino-5,6-dihydrobenzo[h]quinazolines, previously reported as antiplatelet and analgesic/anti-inflammatory agents respectively, we designed and synthesized a new series of 5,6-dihydrobenzo[h]quinazoline 2,4-diamino substituted. The insertion of amino substituents at positions 2 and 4 of the benzoquinazoline scaffold resulted in compounds endowed with a potent ASA-like antiplatelet activity, combined with an anti-inflammatory activity comparable, in some cases, to that of indomethacin, used as a reference drug.     

Design, synthesis, and biological evaluation of substituted hydrazone and pyrazole derivatives as selective COX-2 inhibitors: Molecular docking study

New arylhydrazone derivatives and a series of 1,5-diphenyl pyrazoles were designed and synthesized from 1-(4-chlorophenyl)-4,4,4-trifuorobutane-1,3-dione 1. The newly synthesized compounds were investigated in vivo for their anti-inflammatory activities using carrageenan-induced rat paw oedema model. Moreover, they were tested for their inhibitory activity against ovine COX-1 and COX-2 using an in vitro cyclooxygenase (COX) inhibition assay. Some of the new compounds (2f, 6a and 6d) showed a reasonable in vitro COX-2 inhibitory activity, with IC?? value of 0.45 μM and selectivity index of 111.1. A virtual screening was carried out through docking the designed compounds into the COX-2 binding site to predict if these compounds have analogous binding mode to the COX-2 inhibitors. Docking study of the synthesized compounds 2f, 6a and 6d into the active site of COX-2 revealed a similar binding mode to SC-558, a selective COX-2 inhibitor.     

Synthesis and anti-inflammatory activity of some new 4,5-dihydro-1,5-diaryl-1H-pyrazole-3-substituted-heteroazole derivatives

A series of 4,5-dihydro-1,5-diaryl-1H-pyrazole-3-substituted-heteroazoles were designed and synthesized in order to obtain new compounds with potential anti-inflammatory activity. The title compounds were screened for in vivo anti-inflammatory activity by using Carrageenan induced rat paw edema method. Diclofenac sodium was used as a standard drug for comparison. Out of the 30 compounds tested, compound 19a, 19b, 25a, 25b exhibited significant anti-inflammatory activity. Selected compounds were also screened for in vitro COX-2 inhibition assay and analgesic activity in the acetic acid induced writhing model.     

Synthesis of some pyrazolyl benzenesulfonamide derivatives as dual anti-inflammatory antimicrobial agents

Four series of pyrazolylbenzenesulfonamide derivatives were synthesized and evaluated for their anti-inflammatory activity using cotton pellet induced granuloma and carrageenan-induced rat paw edema bioassays. Moreover, COX-1 and COX-2 inhibitory activity, ulcerogenic effect and acute toxicity were also determined. Furthermore, the target compounds were screened for their in-vitro antimicrobial activity against Eischerichia coli, Staphylococcus aureus and Candida albicans. Compounds 4-(3-Phenyl-4-cyano-1H-pyrazol-1-yl)benzenesulfonamide 9a and 4-(3-Tolyl-4-cyano-1H-pyrazol-1-yl)benzenesulfonamide 9b were not only found to be the most active dual anti-inflammatory antimicrobial agents in the present study with good safety margin and minimal ulcerogenic effect but also exhibited good selective inhibitory activity towards COX-2. A docking pose for 9a and 9b separately in the active site of the human COX-2 enzyme was also obtained. Therefore, these compounds would represent a fruitful matrix for the development of dual anti-inflammatory antimicrobial candidates with remarkable COX-2 selectivity.     

Design and synthesis of 3-pyrazolyl-thiophene, thieno[2,3-d]pyrimidines as new bioactive and pharmacological activities

Two series of 5-ethyl-2-amino-3-pyrazolyl-4-methylthiophenecarboxylate and 2-thioxo-N(3)-aminothieno[2,3-d]pyrimidines were prepared from 3,5-diethyl-2-amino-4-methylthio-phenecaboxylate and evaluated as anti-inflammatory, analgesic and ulcerogenic activities. Among the compounds studied, compounds which containing the substituted hydrazide at C-3 position 7, 16, and 17a showed more potent anti-inflammatory and analgesic activities than the standard drug (Indomethacin and Aspirin), along without ulcerogenity. While compounds 2, 5, 9, 10, and 11c showed moderate activities. Some of the newly synthesized compounds have good to excellent antimicrobial activity.     

Synthesis and screening for acetylcholinesterase inhibitor activity of some novel 2-butyl-1,3-diaza-spiro[4,4]non-1-en-4-ones: derivatives of irbesartan key intermediate

The association of bioactive nucleus with other pharmacological agents is hoped to improve the efficacy of the treatment by combining the effects of different pharmacological mechanisms of action. Keeping this in view, a series of 2-butyl-1,3-diaza-spiro[4,4]non-1-en-4-one derivatives have been synthesized by interaction of 2-butyl-1,3-diaza-spiro[4,4]non-1-en-4-one with different bioactive aralkyl halides in presence of powdered potassium carbonate by two different methods viz., conventional and microwave irradiation. The yields under conventional and microwave irradiation methods were in the range of 60-65% and 80-90%, respectively. The structure elucidation of the new compounds has been carried out with the help of elemental analysis and spectral data. All the synthesized compounds have been screened for their efficacy as acetylcholinesterase (AChE) inhibitor. AChE inhibitory activity study was carried out by using Ellman colorimetric assay with neostigmine as a reference standard against targets from different species, such as pure electric eel AChE, human serum AChE, and rat brain AChE. Among the compounds synthesized, compounds 5a, 5b, 5j showed good inhibition against AChE.     

Design, synthesis, and preliminary in vitro and in vivo pharmacological evaluation of 2-{4-[4-(2,5-disubstituted thiazol-4-yl)phenylethyl]piperazin-1-yl}-1,8-naphthyridine-3-carbonitriles as atypical antipsychotic agents

A series of 2-{4-[4-(2,5-disubstituted thiazolyl)phenylethyl] piperazin-1-yl}-1,8-naphthyridine-3-carbonitriles were synthesized in an effort to prepare novel atypical antipsychotic agents. The compounds were synthesized either by microwave irradiation technique or by conventional synthesis and were characterized by spectral data (IR, (1)H NMR, and MS) and the purity was ascertained by microanalysis. The D(2) and 5-HT(2A) affinity of the synthesized compounds was screened in vitro by radioligand displacement assays on membrane homogenates isolated from rat striatum and rat cortex, respectively. Furthermore, all the synthesized compounds were screened for their in vivo pharmacological activity in Swiss albino mice. The D(2) antagonism studies were performed using climbing mouse assay model and 5-HT(2A) antagonism studies were performed using quipazine-induced head twitches in mice. It was observed that none of the new chemical entities exhibited catalepsy and 10f is the most active among the synthesized compounds with 5-HT(2A)/D(2) ratio of 1.1286 although the standard drug risperidone exhibited 5-HT(2A)/D(2) ratio of 1.0989.