Methylsulfonyl Pharmacophore Research Articles

Design, Synthesis, In vitro and In vivo Evaluation of New Imidazo[1,2-a]pyridine Derivatives as Cyclooxygenase-2 Inhibitors.

Cyclooxygenase-2 (COX-2), the key enzyme in the arachidonic acid conversion to prostaglandins, is one of the enzymes associated with different pathophysiological conditions, such as inflammation, cancers, Alzheimer's, and Parkinson's disease. Therefore, COX-2 inhibitors have emerged as potential therapeutic agents in these diseases. The objective of this study was to design and synthesize novel imidazo[1,2-a]pyridine derivatives utilizing rational design methods with the specific aim of developing new potent COX-2 inhibitors. Additionally, we sought to investigate the biological activities of these compounds, focusing on their COX-2 inhibitory effects, analgesic activity, and antiplatelet potential. We aimed to contribute to the development of selective COX-2 inhibitors with enhanced therapeutic benefits. Docking investigations were carried out using AutoDock Vina software to analyze the interaction of designed compounds. A total of 15 synthesized derivatives were obtained through a series of five reaction steps. The COX-2 inhibitory activities were assessed using the fluorescent Cayman kit, while analgesic effects were determined through writing tests, and Born's method was employed to evaluate antiplatelet activities. The findings indicated that the majority of the tested compounds exhibited significant and specific inhibitory effects on COX-2, with a selectivity index ranging from 51.3 to 897.1 and IC50 values of 0.13 to 0.05 μM. Among the studied compounds, derivatives 5e, 5f, and 5j demonstrated the highest potency with IC50 value of 0.05 μM, while compound 5i exhibited the highest selectivity with a selectivity index of 897.19. In vivo analgesic activity of the most potent COX-2 inhibitors revealed that 3-(4-chlorophenoxy)-2-[4-(methylsulfonyl) phenyl] imidazo[1,2-a]pyridine (5j) possessed the most notable analgesic activity with ED50 value of 12.38 mg/kg. Moreover, evaluating the antiplatelet activity showed compound 5a as the most potent for inhibiting arachidonic acidinduced platelet aggregation. In molecular modeling studies, methylsulfonyl pharmacophore was found to be inserted in the secondary pocket of the COX-2 active site, where it formed hydrogen bonds with Arg-513 and His-90. The majority of the compounds examined demonstrated selectivity and potency as inhibitors of COX-2. Furthermore, the analgesic effects observed of potent compounds can be attributed to the inhibition of the cyclooxygenase enzyme.

Novel secondary pyridinyl amides: Synthesis, in vitro antiproliferative screenings, and molecular docking studies

A novel series of secondary pyridinyl amides, reinforced with the methylsulfonyl pharmacophore unit, was designed and synthesized. Further, we determined the antiproliferative activities of these compounds through experimental assays and analyzed their interactions with Breakpoint Cluster Region/Abelson (bcr/abl), Epidermal Growth Factor Receptor (EGFR), and Human Epidermal Growth Factor Receptor 2 (HER2) tyrosine kinases using molecular autodocking techniques. We grouped these amides into three categories, classified by the type of spacer that binds the pyridine ring to the amide nitrogen atom. Additionally, within each group, we strategically positioned the amide moiety at the ortho, meta, or para position on the pyridyl ring. Among the studied amides, compound 3 exhibited the best overall antiproliferative activity against human immortalized myelogenous leukemia (K562) (IC50 = 26 µM), human leukemia monocytic cell line (THP-1) (IC50 = 81 µM), and human hepatocellular carcinoma (HepG2) (IC50 = 210 µM). Molecular docking studies revealed that compound 3 binds effectively to bcr/abl, EGFR, and HER2 tyrosine kinases, demonstrating strong interactions with crucial active site amino acids, indicative of its targeted antiproliferative mechanism. All investigated compounds showed either very minor or no cytotoxicity against human dermal fibroblast adult cells.

Synthesis of New Compounds Bearing Methyl Sulfonyl Pharmacophore As Selective COX-2 Inhibitor.

Cyclooxygenase, also known as prostaglandin H2 synthase (PGH2), is one of the most important enzymes in pharmacology because inhibition of COX is the mechanism of action of most nonsteroidal anti-inflammatory drugs. In this study, ten thiazole derivative compounds had synthesized. The analysis of the obtained compounds was performed by 1 H NMR and 13 C NMR methods. By this method, the obtained compounds could be elucidated. The inhibitory effect of the obtained compounds on cyclooxygenase (COX) enzymes investigated. The encoded compounds 5a, 5b, and 5c were found to be the most potent compared to the reference compounds ibuprofen (IC50 =5.589±0.278 μM), celecoxib (IC50 =0.132±0.004 μM), and nimesulide (IC50 =1.692±0.077 μM)against COX-2 isoenzyme. The inhibitory activity of 5a, 5b, and 5c is approximate, but the 5a derivative proved to be the most active in the series with an IC50 value of 0.180 ± 0.002 μM The most potent COXs inhibitor was 5a, which further investigated for its potential binding mode by molecular docking study. Compound 5a found to be localized at the active site of the enzyme, like celecoxib, which has a remarkable effect on COXs enzymes. This article is protected by copyright. All rights reserved.

Novel Benzo[4,5]imidazo[1,2-a]pyrimidine derivatives as selective Cyclooxygenase-2 Inhibitors: Design, synthesis, docking studies, and biological evaluation

The present study was aimed at the synthesis and evaluation of a new series of benzo[4,5]imidazo[1,2-a]pyrimidine having a methylsulfonyl group as COX-2 (cyclooxygenase-2) inhibitor pharmacophore. Molecular modeling studies were performed using the Autodock program, and the results demonstrated that methylsulfonyl pharmacophore was adequately placed into the COX-2 active site. The in vitro and in vivo COX-2 inhibitory effects were also evaluated. In the in vitro assay, all newly synthesized compounds showed moderate to good selectivity for the inhibition of the COX-2 enzyme. However, compound 2-(4-(methylsulfonyl) phenyl)-4-phenylbenzo[4,5]imidazo[1,2-a]pyrimidine (5a) showed the highest COX-2 inhibitory effect (IC50: 0.05 μM) even more than celecoxib as the reference drug (IC50: 0.06 μM). For the in vivo study, the writing reflex test was used, and the results indicated that all synthesized compounds had well dose-dependent anti-nociceptive activity. The in vivo evaluation also showed that compound 2-(4-(methylsulfonyl)phenyl)-4-(p-tolyl)benzo[4,5]imidazo[1,2-a]pyrimidine (5d) had the highest activity in the writing reflex test (ED50: 5.75 mg/kg). In addition, the cytotoxicity effects of the synthesized compounds were tested on MCF-7 breast cancer cells, and all compounds showed considerable inhibitory results.

Design, Synthesis, Docking Studies, Enzyme Inhibitory and Antiplatelet Aggregation Activities of New 1,3-Diphenyl-3-(Phenylthio)Propan-1-One Derivatives as Selective COX-2 Inhibitors.

Cancer is the second leading cause of death worldwide after heart disease. A vast number of studies indicated that selective cyclooxygenase-2 (COX-2) inhibitors could be chemopreventive against different types of cancer because the expression of COX-2 is increased. Therefore, to develop new therapeutics for cancer, the design and synthesis of new COX-2 inhibitors with few side effects seem attractive as anti-cancer agents. Some of the well-known drugs that have been widely used for some time have been removed from the market due to the cardiac side effects they cause, so there is a need to introduce a scaffold that can inhibit COX-2 with high potency and low side effects. This study aimed to introduce a new COX-2 inhibitor structure. A new series of β-aryl-β-mercapto ketones possessing a methylsulfonyl pharmacophore was synthesized and evaluated as selective COX-2 inhibitors. In-vitro COX-1 and COX-2 inhibition effects of these compounds were evaluated, and molecular modeling was examined. Also, the antiplatelet aggregation activity of the synthesized compounds was tested. In-vitro COX-1 and COX-2 inhibition assays indicated that almost all newly synthesized compounds showed selectivity for COX-2 with IC50 values in the 0.07-0.22 μM range and COX-2 selectivity indexes in the 170 to 703.7 range. Among the tested compounds 1-(4-(methylsulfonyl)phenyl)-3-phenyl-3-(phenylthio)propan-1-one (4a), 3-(3,4- dimethoxyphenyl)-1-(4-(methylsulfonyl)phenyl)-3-(phenylthio)propan-1-one (4g) and 3-(4-fluorophenyl)-1-(4-(methyl sulfonyl)phenyl)-3-(phenylthio)propan-1-one (4h) were the most potent COX-2 inhibitors and 3-(3,4- dimethoxyphenyl)-1-(4-(methylsulfonyl)phenyl)-3-(phenylthio)propan-1-one had the highest selectivity index for COX-2 enzyme inhibitory activity. The Anti-platelet aggregation activity results indicated that the compound 1-(4- (methylsulfonyl)phenyl)-3-(phenylthio)-3-(p-tolyl)propan-1-one (4b) possesses the strong anti-platelet activity. Our molecular modeling studies also indicated that the methylsulfonyl pharmacophore group is placed into the adjunct pocket in the COX-2 active site and forms hydrogen bond interactions with NH of Arg513 and NH of His90. In brief, all designed and synthesized compounds showed moderate to good COX-2 inhibitory effects and showed good anti-platelet activity. Therefore, these compounds have the potential for further research into developing anti-cancer agents.

Design, Synthesis and Biological Evaluation of New N-Acyl Hydrazones with a Methyl Sulfonyl Moiety as Selective COX-2 Inhibitors.

The mechanism of action of nonsteroidal anti-inflammatory drugs (NSAIDs) is inhibition of specific prostaglandin (PG) synthesis by inhibition of cyclooxygenase (COX) enzymes. The two COX isoenzymes show 60 % similarity. It is known that the nonspecific side effects of conventional NSAIDs are physiologically caused by inhibition of the COX-1 enzyme. Therefore, the use of COX-2 selective inhibitors is seen to be a more beneficial approach in reducing these negative effects. However, some of the existing COX-2 selective inhibitors show cardiovascular side effects. Therefore, studies on the development of new selective COX-2 inhibitors remain necessary. It is important to develop new COX-2 inhibitors in the field of medicinal chemistry. Accordingly, novel N-acyl hydrazone derivatives were synthesized as new COX-2 inhibitors in this study. The hydrazone structure, also known for its COX activity, is important in terms of many biological activities and was preferred as the main structure in the design of these compounds. A methyl sulfonyl pharmacophore was added to the structure in order to increase the affinity for the polar side pocket present in the COX-2 enzyme. It is known that methyl sulfonyl groups are suitable for polar side pockets. The synthesis of the compounds (3a-3j) was characterized by spectroscopic methods. Evaluation of in vitro COX-1/COX-2 enzyme inhibition was performed by fluorometric method. According to the enzyme inhibition results, the obtained compounds displayed the predicted selectivity for COX-2 enzyme inhibition. Compound 3j showed important COX-2 inhibition with a value of IC50 =0.143 uM. Interaction modes between the COX-2 enzyme and compound 3j were investigated by docking studies.

Design, synthesis, and biological evaluation of new 1,4-diarylazetidin-2-one derivatives (β-lactams) as selective cyclooxygenase-2 inhibitors.

A new series of 1,4-diarylazetidin-2-one derivatives (β-lactams) were designed and synthesized to evaluate their biological activities as selective cyclooxygenase-2 (COX-2) inhibitors. In vitro COX-1 and COX-2 inhibition studies showed that all compounds were selective inhibitors of the COX-2 isozyme with IC50 values in the 0.05-0.11 µM range, and COX-2 selectivity indexes in the range of 170-703.7. Among the synthesized β-lactams, 3-methoxy-4-(4-(methylsulfonyl)phenyl)-1-(3,4,5-trimethoxyphenyl)azetidin-2-one (4j) possessing trimethoxy groups at the N-1 phenyl ring exhibited the highest COX-2 inhibitory selectivity and potency, even more potent than the reference drug celecoxib. The analgesic activity of the synthesized compounds was also determined using the formalin test. Compound 4f displayed the best analgesic activity among the synthesized molecules. Molecular modeling studies indicated that the methylsulfonyl pharmacophore group can be inserted into the secondary pocket of the COX-2 active site for interactions with Arg513 . The structure-activity data acquired indicate that the β-lactam ring moiety constitutes a suitable scaffold to design new 1,4-diarylazetidin-2-ones with selective COX-2 inhibitory activity.

Design, Synthesis, and Biological Evaluation of New 2-Phenyl-4H-chromen-4-one Derivatives as Selective Cyclooxygenase-2 Inhibitors.

In order to develop new selective COX-2 inhibitors, a new series of 2-phenyl-4H-chromen-4-one derivatives possessing a methylsulfonyl pharmacophore group at the para position of the C-4 phenyl ring were designed, synthesized, and evaluated for cyclooxygenase-2 inhibitory activity. In vitro COX-1/COX-2 isozyme inhibition structure-activity studies identified 3-(benzyloxy)-2-[4-(methylsulfonyl)phenyl]-4H-chromen-4-one (5d) as a potent COX-2 inhibitor (IC50 = 0.07 μM) with a high COX-2 selectivity index (SI = 287.1) comparable to the reference drug celecoxib (COX-2 IC50 = 0.06 μM; COX-2 SI = 405). A molecular modeling study where 3-(benzyloxy)-2-[4-(methylsulfonyl)phenyl]-4H-chromen-4-one (5d) was docked into the active site of COX-2 showed that the p-MeSO2 substituent on the C-4 phenyl ring was well-oriented in the vicinity of the COX-2 secondary pocket (Arg513, Val523, and His90) and the carbonyl group of the chromene ring could interact with Ser530. The structure-activity data acquired indicated that the nature and size of the substituent on the C-3 chromene scaffold are important for COX-2 inhibitory activity. Our results also indicated that the chromene moiety constitutes a suitable template to design new COX-2 inhibitors.

Synthesis and biologic evaluation of new 3-phenoxyazetidin-2-one derivatives as selective cyclooxygenase-2 inhibitors

A new series of 3-phenoxyazetidin-2-ones (β-lactams) were designed and synthesized for the evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. In vitro COX-1 and COX-2 inhibition studies showed that all compounds were selective inhibitors of the COX-2 isozyme with IC50 values in the 0.054–0.095 μM range, and COX-2 selectivity indexes in the 228.47–355.6 range. Among the synthesized compounds, 1-(4-methoxyphenyl)-4-(4-(methylsulfonyl)phenyl)-3-phenoxyazetidin-2-one (4j) possessing methoxy group at the para position of N-1 phenyl ring exhibited the highest COX-2 inhibitory selectivity and potency even more potent than the reference drug celecoxib. Molecular modeling studies indicated that the methylsulfonyl pharmacophore group can be inserted into the secondary pocket of COX-2 active site.

Design and Synthesis of New 1,3‐Benzdiazinan‐4‐one Derivatives as Selective Cyclooxygenase (COX‐2) Inhibitors

A new group of regioisomeric 2,3-diaryl-1,3-benzdiazinan-4-ones, possessing a methyl sulfonyl pharmacophore, were synthesized and their biological activities were tested for cyclooxygenase-2 (COX-2) inhibitory activity. In vitro COX-1/COX-2 inhibition studies identified 3-(p-fluorophenyl)-2-(4-methylsulfonylphenyl)-1,3-benzdiazinane-4-one (2b) as a potent and highly selective (IC(50) = 0.07 µM; selectivity index = 572.8) COX-2 inhibitor.

Design and synthesis of new 1,2-diaryl-4,5,6,7-tetrahydro-1H-benzo[d] imidazoles as selective cyclooxygenase (COX-2) inhibitors

A new series of 1,2-diaryl-4,5,6,7-tetrahydro-1H-benzo[d]imidazoles, possessing a methylsulfonyl pharmacophore, were synthesized to evaluate their biological activities as selective cyclooxygenase-2 (COX-2) inhibitors. In vitro COX-1 and COX-2 isozyme inhibition studies were carried out to acquire structure–activity relationship data with respect to the point that molecular modeling studies showed that designed compounds bind in the primary binding site such that the SO2Me substituent at para-position of C-2 phenyl ring inserts into the 2° pocket present in COX-2 enzyme. COX-1 and COX-2 inhibition studies showed that all compounds were selective inhibitors of the COX-2 isozyme with IC50 values in the highly potent 0.34–0.69 μM range, and COX-2 selectivity indexes in the 52.3–163.8 range. 1-(4-Fluorophenyl)-2-(4-(methylsulfonyl)phenyl)-4,5,6,7-tetrahydro-1H-benzo[d] imidazole was identified as the most potent (IC50 = 0.34 μM), and selective (SI = 163.8), COX-2 inhibitor among the synthesized compounds.

Design and synthesis of new 2,4,5-triarylimidazole derivatives as selective cyclooxygenase (COX-2) inhibitors

A new group of 2,4,5-triarylimidazole derivatives, possessing a methyl sulfonyl pharmacophore, were synthesized and their biological activities were evaluated for cyclooxygenase-2 (COX-2) inhibitory activity. In vitro COX-1/COX-2 structure–activity relationships were determined by varying the substituents at the para position of C-2 phenyl ring. Among the 2,4,5-triarylimidazoles, 2-(4-hydroxy phenyl)-4-(4-methylsulfonylphenyl)-5-phenyl-1H imidazole (11f) was identified as a selective COX-2 inhibitor (COX-2 IC50 = 0.15 μM; selectivity index = 75) that was less potent than the reference drug celecoxib (COX-2 IC50 = 0.06 μM; SI = 405). A molecular modeling study where 11f was docked in the binding site of COX-2 showed that the methylsulfonyl pharmacophore group is oriented in the vicinity of the COX-2 secondary pocket (Arg513, Phe518, Gly519, and Val523). The structure–activity data acquired indicate that COX-1/COX-2 inhibition is sensitive to the nature of the C-2 phenyl substituents.

Design and synthesis of new 2-aryl, 3-benzyl-(1,3-oxazolidine or 1,3-thiazolidine)-4-ones as selective cyclooxygenase (COX-2) inhibitors

A new series of 2-aryl, 3-benzyl-(1,3-oxazolidine or 1,3-thiazolidine)-4-ones, possessing a methylsulfonyl pharmacophore, were synthesized to evaluate their biological activities as selective cyclooxygenase-2 (COX-2) inhibitors. In vitro COX-1 and COX-2 isozyme inhibition studies were performed to acquire structure-activity relationship data with respect to the point that molecular modeling studies showed that designed compounds bind in the primary binding site such that the C-2 para-SO2Me substituent inserts into the 2° pocket present in COX-2 enzyme. COX-1 and COX-2 inhibition studies showed that all compounds were selective inhibitors of the COX-2 isozyme with IC50 values in the highly potent 0.21 to 0.34 μM range, and COX-2 selectivity indexes in the 222.3 to >476 range. 3-Benzyl-2-(4-methylsulfonylphenyl)-1,3-oxazolidine-4(5H)-one was identified as the most potent (IC50 = 0.21 μM) and selective (S.I. > 476) COX-2 inhibitor among the synthesized compounds. It also was a more selective COX-2 inhibitor than the parent reference compound celecoxib (S.I. > 403).

Design and synthesis of new 1,3-benzthiazinan-4-one derivatives as selective cyclooxygenase (COX-2) inhibitors

A new group of 1, 3-benthiazinan-4-ones, possessing a methyl sulfonyl pharmacophore, were synthesized and their biological activities were evaluated for cyclooxygenase-2 (COX-2) inhibitory activity. In vitro COX-1/COX-2 inhibition studies identified 3-( p-fluoropheny)-2-(4-methylsulfonylphenyl)-1,3-benzthiazinan-4-one ( 7b) as a potent (IC 50 = 0.05 μM) and selective (selectivity index = 259) COX-2 inhibitor.

Design and synthesis of 3-alkyl-2-aryl-1,3-thiazinan-4-one derivatives as selective cyclooxygenase (COX-2) inhibitors

A new group of 3-alkyl-2-aryl-1,3-thiazinan-4-ones, possessing a methylsulfonyl pharmacophore, were synthesized and their biological activities were evaluated for cyclooxygenase-2 (COX-2) inhibitory activity. In vitro COX-1/COX-2 inhibition studies identified 3-benzyl-2-(4-methylsulfonylphenyl)-1,3-thiazinan-4-one ( 11a) as a potent (IC 50 = 0.06 μM) and selective (selectivity index >285) COX-2 inhibitor.

Design and synthesis of 1,3-diarylurea derivatives as selective cyclooxygenase (COX-2) inhibitors

A group of 1,3-diarylurea derivatives, possessing a methylsulfonyl pharmacophore at the para-position of the N-1 phenyl ring, in conjunction with a N-3 substituted-phenyl ring (4-F, 4-Cl, 4-Me, 4-OMe), were designed and synthesized for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. In vitro COX-1/COX-2 isozyme inhibition structure-activity studies identified 1-(4-methylsulfonylphenyl)-3-(4-methoxyphenyl) urea (4e) as a potent COX-2 inhibitor (IC(50)=0.11 microM) with a high COX-2 selectivity index (SI=203.6) comparable to the reference drug celecoxib (COX-2 IC(50)=0.06 microM; COX-2 SI=405). The structure-activity data acquired indicate that the urea moiety constitutes a suitable scaffold to design new acyclic 1,3-diarylurea derivatives with selective COX-2 inhibitory activity.

Synthesis of 2,3-diaryl-1,3-thiazolidine-4-one derivatives as selective cyclooxygenase (COX-2) inhibitors

A group of 2,3-diaryl-1,3-thiazolidine-4-ones, possessing a methylsulfonyl pharmacophore, were synthesized and their biological activities were evaluated for cyclooxygenase-2 (COX-2) inhibitory activity.

Design and Synthesis of Novel Rofecoxib Analogues as Potential Cyclooxygenase (COX‐2) Inhibitors: Replacement of the Methylsulfonyl Pharmacophore by a Sulfonylazide Bioisostere.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Design and synthesis of novel rofecoxib analogs as potential cyclooxygenase (COX‐2) inhibitors: Replacement of the methylsulfonyl pharmacophore by a sulfonylazide bioisostere

AbstractA group of rofecoxib analogs, having a sulfonylazide (SO2N3) substituent in place of the methanesulfonyl (SO2CH3) pharmacophore at the meta‐position viz 3‐(4‐methyl, 4‐methoxy, or 4‐ethoxyphenyl)‐4‐(3‐sulfonylazidophenyl)‐2(5H)furanone (7a‐c) and para‐position viz 3‐phenyl‐4‐(4‐sulfonylazidophenyl)‐2(5H)furanone (7d), 3‐(4‐fluoro, or 4‐chlorophenyl)‐4‐(4‐sulfonylazidophenyl)‐2(5H)furanone (7e‐f) of the C–4 phenyl ring, and 4‐(1‐oxido‐4‐pyridyl)‐3‐phenyl‐2(5H)furanone (12) were designed and synthesized for evaluation as selective cyclooxygenase‐2 (COX‐2) inhibitors. In vitro COX‐1/COX‐2 enzyme inhibition studies showed that 3‐phenyl‐4‐(4‐sulfonylazidophenyl)‐2(5H)furanone (7d) inhibited COX‐1 selectively (COX‐1 IC50 = 0.6659 μM; COX‐2 IC50 > 100 μM) and 3‐(4‐fluorophenyl)‐4‐(4‐sulfonylazidophenyl)‐2(5H)furanone (7e) inhibited both enzymes (COX‐1 IC50 = 0.8494 μM; COX‐2 IC50 = 1.7661 μM). A molecular modeling study was performed where 3‐(4‐fluorophenyl)‐4‐(4‐sulfonylazidophenyl)‐2(5H)furanone (7e) was docked in the active site of murine COX‐2 isozyme, which showed that the sulfonylazido group inserts deep into the 2°‐pocket of COX‐2 where it undergoes both H‐bonding (Gln192, Phe518) and weak electrostatic (Arg513) interactions.