α-Aroylketene Dithioacetal Mediated Synthesis of (E)-3-(benzo[d]thiazol-2-ylamino)-2-(1-methyl-1H-indole-3-carbonyl)-3-(methylthio)acrylonitrile Derivatives and their Biological Evaluation.

BACKGROUND: The blending of two pharmacophores would generate novel molecular templates that are likely to exhibit interesting biological properties. OBJECTIVE: A facile, efficient and high yielding synthesis of (E)-3-(benzo[d]thiazol-2-ylamino)-2-(1-methyl-1Hindole- 3-carbonyl)-3-(methylthio) acrylonitrile derivatives and evaluation of therapeutic potential. METHOD: The synthesis of target molecules has been achieved by reacting 2-aminobenzothiazole and substituted 2-(1-methyl-1H-indole-3-carbonyl)-3,3-bis(methylthio)acrylonitrile in the presence of a catalytic amount of sodium hydride in THF. Structural investigations were carried using 1H NMR, 13C NMR, FT-IR, and HRMS data. RESULTS: In vitro anti-tumor evaluation of the synthesized compounds against MCF-7 (breast carcinoma) cell line revealed that they possess good anti-tumor activities. Compounds, 4j and 4i demonstrated significant activities against breast carcinoma (GI50 14.3 and 19.5 µM respectively). Most of the synthesized compounds were also found to be excellent NO, H2O2, DPPH, and superoxide radical scavengers. Anti-diabetic and antiinflammatory evaluation also displayed moderate activity. CONCLUSION: Among the compounds synthesized some of the compounds possess significant anticancer, antioxidant and anti-inflammatory properties.

Synthesis of extended conjugated indolyl chalcones as potent anti-breast cancer, anti-inflammatory and antioxidant agents.

In the present investigation, synthesis of a series of extended conjugated δ-chloro-α-cyano substituted indolyl chalcones (5a-p) was accomplished by reacting 3-cyanoacetylindole 2 with 3-chloro-3-phenyl-propenal 4 in the presence of piperidine. The structural interpretations of newly synthesized compounds were based on chemical and spectroscopic evidences. Anti-tumor evaluation of the synthesized compounds in vitro against MCF-7 (breast carcinoma) cell line revealed that they possess high anti-tumor activities. Among them, compound 5e and 5a demonstrated excellent activity against breast carcinoma (GI50 <0.1 and 4µM respectively) as good as adriamycin (GI50 <0.1µM). The compounds were also screened against the normal Vero monkey cell line, which showed moderate selectivity against inhibition of cancer cells. The effect of extended conjugation on activity authenticated by comparing activity profile of compound 5a, 5i and 5m with their simple analogues. Among the synthesized compounds, 5i and 5l were found to be active anti-inflammatory agents in addition to having noteworthy antioxidant potential. These results suggest the possible use of these compounds for the design and development of novel anti-breast cancer agents.

Preparation and Pharmacological Evaluation of Novel Orally Active Ester Prodrugs of Ketoprofen with Non-Ulcerogenic Property.

This study investigates anti-inflammatory activity with improved pharmacokinetic and non-ulcerogenic properties of various novel synthesized prodrugs of ketoprofen in experimental animals. Prodrugs 3a, 3f and 3k were found to possess significant anti-inflammatory activity with almost non-ulcerogenic potential than standard drug ketoprofen (1) in both normal and inflammation-induced rats. The experimental findings elicited higher AUC and plasma concentration at 1 and 2 h indicating improved oral bioavailability as compared to parent drug ketoprofen. These prodrugs are found to have no gastric ulceration with retained anti-inflammatory activity. Therefore, present experimental findings demonstrated significant improvement of various pharmacokinetic properties with non-ulcerogenic potential of ester prodrugs of ketoprofen.

Design, synthesis, characterization and in vitro and in vivo anti-inflammatory evaluation of novel pyrazole-based chalcones.

Abstract A series of novel pyrazole-based chalcones have been designed, synthesized from 1-methyl-5-(2,4,6-trimethoxyphenyl)-1H-pyrazole (6). The structures of regioisomers 6 and 7 were determined by 2D (1)H-(1)H COSY, (1)H-(13)C HSQC and (1)H-(13)C HMBC experiments. The newly synthesized compounds were tested for their inhibitory activity against COX-1 and COX-2 using an in vitro cyclooxygenase (COX) inhibition assay. Moreover, they were investigated in vivo for their anti-inflammatory activities using carrageenan-induced rat paw edema model for acute inflammation and cotton pellet-induced granuloma model for chronic inflammation. All the synthesized compounds showed potential to demonstrate anti-inflammatory activities, of particular interest compounds 10i, 10e, 10f, and 10h were found to be potent anti-inflammatory agents.

Synthesis and biological evaluation of asymmetric indole curcumin analogs as potential anti-inflammatory and antioxidant agents.

Abstract A series of asymmetric indole curcumin analogs were synthesized and evaluated as possible inhibiters of pro-inflammatory enzymes such as COX-2, pro-inflammatory cytokines as TNF-α and IL-6, trypsin and ß-glucuronidase. They were also tested for antioxidant activities. The results showed that compounds 5e and 5h were found to be the most potent inhibitors of COX-2 (83.33%, 82.50%) and ß-glucuronidase (67.80%, 64.12%). All the synthesized compounds exhibited promising activity against IL-6 in a range of 71-100% at 10 µM concentration. Compounds 5f, 5h, 5e, 5c and 5d showed significant inhibition against TNF-α (28-51%) and IL-6 (87-98%) with low toxicity (45-51%) against CCK-8 cells. With few exceptions, all other compounds were found to be good to excellent inhibitors of IL-6 and moderate inhibitors of TNF-α; however, the toxicity profiles of these compounds need to be ameliorated in further optimization studies. Amongst the tested compounds, 5c, 5b, 5j and 5g were found to possess excellent reducing activity and 5b, 5c and 5h were moderate DPPH (1,1-diphenyl-2-picryl hydrazine) radical scavengers.

Synthesis of new heterocyclic hybrids based on pyrazole and thiazolidinone scaffolds as potent inhibitors of tyrosinase.

As a part of ongoing studies in developing new Tyrosinase inhibitors, a class of structurally novel 2-(2,4-dimethoxy phenylamino)-5 methylene-4-thiazolinone derivatives were synthesized by incorporating 2-(2,4-dimethoxy-phenylamino)-thiazol-4-one with various 1-(1-methyl-buta-1,3-dienyl)-3-phenyl-1H-pyrazole-4-carbaldehyde. The results showed that some of the synthesized compounds exhibited significant inhibitory activities. Especially, 5-[3-(2-chloro-phenyl)-1-phenyl-1H-pyrazol-4-ylmethylene]-2-(2,4-dimethoxy-phenylamino)-thiazol-4-one (5h) and 5-[3-(3-chloro-phenyl)-1-phenyl-1H-pyrazol-4-ylmethylene]-2-(2,4-dimethoxy-phenylamino)-thiazol-4-one (5g) possessing 2-chloro-phenyl and 3-chloro-phenyl group exhibited the most potent tyrosinase inhibitory activity with an IC(50) value of 34.12 and 52.62 µM, respectively. The inhibition mechanism analysis of 5h and 5g thiazolidinone derivatives demonstrated that the inhibitory effects of the compounds on tyrosinase were reversible and competitive. Preliminary structure-activity relationships (SAR) analysis suggested that further development of such compounds might be of interest, as it manifests simple reversible slow binding inhibition against monophenolase and diphenolase.

Design, synthesis, characterization and biological evaluation of novel pyrazole integrated benzophenones.

A series of novel pyrazole integrated benzophenones (9a-j) have been designed, synthesized from 1-methyl-5-(2,4,6-trimethoxy-phenyl)-1H-pyrazole 6. The structures of the regioisomers 6 and 7 were determined by 2D (1)H-(1)H COSY, (1)H-(13)C HSQC and (1)H-(13)C HMBC experiments. The newly synthesized compounds (9a-j) were evaluated for in vivo anti-inflammatory activity by carrageenan paw edema in rats and in vitro COX-1/COX-2 inhibition and antioxidant potential. Among the synthesized compounds, compounds 9b, 9d and 9f, were found to be active anti-inflammatory agents in addition to having potent antioxidant activity.

Design, synthesis, characterization and anti-inflammatory evaluation of novel pyrazole amalgamated flavones.

A series of novel pyrazole amalgamated flavones has been designed and synthesized from 1-methyl-5-(2,4,6-trimethoxy-phenyl)-1H-pyrazole 6. The structures of regioisomers 6 and 7 were resolved by 2D (1)H-(1)H COSY, (1)H-(13)C HSQC and (1)H-(13)C HMBC experiments. The newly synthesized compounds were tested for their in vitro COX inhibition and in vivo carrageenan induced hind paw edema in rats and acetic acid induced vascular permeability in mice. Although the compounds have inhibitory profile against both COX-1 and COX-2, some of the compounds are found to be selective against COX-2, supported by inhibition of paw edema and vascular permeability. Docking studies were also carried out to determine the structural features which sway the anti-inflammatory activity of the tested compounds. The keto and phenolic -OH are major factors that are prominently involved in interaction with COX-2 active site.

Synthesis and biological evaluation of novel series of aminopyrimidine derivatives as urease inhibitors and antimicrobial agents.

A novel series of carbazole substituted aminopyrimidines (5a-p) were synthesized and screened for their in vitro urease inhibition and antimicrobial activity. Among the compounds, 4-(2,4-dichlorophenyl)-6-(9-methyl-9H-carbazol-3-yl)-pyrimidin-2-amine (5i) was found to be the most potent showing urease inhibitory activity with an IC50 value 19.4 ± 0.43 µM. Compounds 5c, 5g, 5j and 5o showed good activity against all selected bacterial strains and compounds 5b, 5c, 5m and 5o showed good activity against selected fungal strains. All the compounds were subjected for ADME predictions by computational method.

Synthesis of novel carbazole chalcones as radical scavenger, antimicrobial and cancer chemopreventive agents.

A series of novel carbazole chalcones has been synthesised and evaluated for radical scavenging activity, cytotoxicity and antimicrobial activities. Compounds 12m, 12o and 12c exhibited good 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, compounds 12e, 12m and 12d were excellent hydroxyl radical scavengers and compounds 12a, 12e, 12g, 12n and 12m have shown inhibition of oxidative DNA damage induced by 2,2'-azobis (2-amidinopropane hydrochloride). Compounds 12j, 12i, 12n, 12c, 12m and 12e were most active against the selected cancer cell lines. Compounds 12a, 12e and 12m showed good antibacterial activity and compounds 12h and 12m have shown good antifungal activity. All the compounds were subjected for absorption, distribution, metabolism and excretion (ADME) predictions by computational method and found that these molecules could be considered as potential candidates for oral drug development.

Synthesis and biological evaluation of ester prodrugs of Benzafibrate as orally active hypolipidemic agents.

A series of bezafibrate ester prodrugs 1-7 were synthesized and evaluated for hypolipidemic activity in Swiss Albino mice (SAM). Bezafibrate (1a), a hypolipidemic drug was used as a reference compound for data comparison. Among the synthesized compounds, prodrug 7 showed superior activities in decreasing triglyceride up to 30% in mice plasma after oral administration of 50mg/kg/day for 8 days. Prodrugs 2, 3, 5, 6, and 7 were found to be more lipophilic than bezafibrate (1a), indicated by partition coefficients measured in octanol-buffer system at pH 7.4. On the basis of in vivo studies, prodrug 7 emerged as new potent hypolipidemic agent.

Synthesis, biological evaluation, and molecular docking of N-{3-[3-(9-methyl-9H-carbazol-3-yl)-acryloyl]-phenyl}-benzamide/amide derivatives as xanthine oxidase and tyrosinase inhibitors.

Claisen-Schmidt condensation of 3-formyl-9-methylcarbazole with various amides of 3-aminoacetophenone afforded N-{3-[3-(9-methyl-9H-carbazol-3-yl)-acryloyl]-phenyl}-benzamide/amide derivatives. All compounds were investigated for their in vitro xanthine oxidase (XO), tyrosinase and melanin production inhibitory activity. Most of the target compounds had more potent XO inhibitory activity than the standard drug (IC(50) = 4.3-5.6 µM). Interestingly, compound 7q bearing cyclopropyl ring was found to be the most potent inhibitor of XO (IC(50) = 4.3 µM). Molecular modelling study gave an insight into its binding modes with XO. Compounds 7a, 7d, 7e, 7g, and 7k were found to be potent inhibitors of tyrosinase (IC(50) = 14.01-17.52 µM). These results suggest the possible use of these compounds for the design and development of novel XO and tyrosinase inhibitors.

Synthesis, biological evaluation, and docking studies of 3-(substituted)-aryl-5-(9-methyl-3-carbazole)-1H-2-pyrazolines as potent anti-inflammatory and antioxidant agents.

A novel series of 3-(substituted)-aryl-5-(9-methyl-3-carbazole)-1H-2-pyrazolines (5a-o) has been synthesized and the structures of newly synthesized compounds were characterized by IR, (1)H NMR and mass spectral analysis. All the synthesized compounds were evaluated for their in vitro and in vivo anti-inflammatory activity, and also for their antioxidant activity. Compounds 5b, 5c, 5d and 5n were found to be selective COX-2 inhibitors. Compound 5c was found to potent inhibitor of the carrageenin induced paw edema in rats. Most of the compounds exhibited good DPPH and superoxide radical scavenging activity, while compounds 5c, 5d, 5i and 5k exhibited good hydroxyl radical scavenging activity. Molecular docking result, along with the biological assay data, suggested that compound 5c was a potential anti-inflammatory agent.

Synthesis and antioxidant, cytotoxicity and antimicrobial activities of novel curcumin mimics.

Claisen-Schmidt condensation of 3-(1,2,3,6-tetrahydro-1-methylpyridin-4-yl)-2,4,5- trimethoxybenzaldehyde 3 and various aromatic, heterocyclic and alicyclic amides of 3- aminoacetophenone 6(a-s) afforded novel curcumin mimics. All the synthesized compounds were characterized by IR, (1)H NMR, Mass spectroscopy and evaluated for antioxidant, cytotoxicity and antimicrobial activity. Out of the 20 compounds screened, compounds 7i, 7l, 7q, and 7n have shown excellent radical scavenging activity, compounds 7o, 7t, 7f, and 7r have shown significant xanthine oxidase inhibition, and compounds 7a, 7k and 7l were found to be potent inhibitors of selected cancer cell lines. Compounds 7h, 7t, 7l, 7i, and 7e have shown good antibacterial activity, whereas compounds 7j, 7f, 7o, 7h, and 7t exhibited significant antifungal activity.

Synthesis and biological evaluation of orally active hypolipidemic agents.

A series of novel fenofibric acid ester prodrugs 1c-1h were synthesized and evaluated with the aim of obtaining potent hypolipidemic agents. Prodrugs 1c and 1d exhibited potent hypochlolesterolemic activity, lowering the mice plasma triglyceride level up to 47% in Swiss albino mice after oral administration of 50 mg/kg/day for 8 days. Fenofibric acid ester prodrugs 1c-1h were found lipophilic like fenofibrate (1b), indicated by partition coefficients measured in octanol-buffer system at pH 7.4. On the basis of in vivo studies, prodrugs 1c and 1d emerged as potent hypolipidemic agents.

Synthesis and biological evaluation of orally active prodrugs of indomethacin.

Synthesis and biological evaluation of orally active prodrugs (1a-d) of indomethacin are described. Prodrugs 1a-c showed a similar degree of anti-inflammatory activity, and prodrug 1d was found to be less potent than the parent drug indomethacin (1). Ulcer index (UI) data indicated that 1a (UI = 19), 1c (UI = 0), and 1d (UI = 0) were substantially less ulcerogenic and 1b (UI = 62) was more ulcerogenic than parent drug 1 (UI = 47). These prodrugs demonstrated good stability at acidic and basic pH and found to be more lipophilic than parent drug compound 1, indicated by partition coefficients measured in octanol-buffer system at pH 7.4 and 3.0. On the basis of in vivo studies, 1a and 1c compounds were selected for metabolic stability in rat liver microsome (RLM) and rat plasma (RP), and both were found to be enzymatically labile. Prodrugs 1a and 1c emerged as potent anti-inflammatory agents with a lesser potential for ulcer than the parent drug indomethacin.

Synthesis, characterization, and biological evaluation of novel diclofenac prodrugs.

Diclofenac ester pro drugs (4, 5, 6) were synthesized and evaluated in vitro and in vivo for their potential use for oral delivery, with the aim of obtaining enzymatically labile and less ulceration drugs than the parent drug diclofenac sodium (1a). Prodrugs 4, 5, 6 were found to be potent anti-inflammatory drugs with less ulcerogenic potential than the parent diclofenac sodium. Prodrugs 4, 5, 6 rapidly underwent enzymatic hydrolysis to release the parent drug diclofenac in 30-60 min in rat liver microsomes (RLM) and rat plasma (RP). Prodrugs were found to be more lipophilic when the partition coefficient was measured in 1-octanol and buffer system at pH 7.4 and 3.0. Diclofenac prodrugs 4, 5, 6 were found to be crystalline in nature (analyzed by PXRD). Prodrug 4 was found to be a superior candidate for the treatment of chronic inflammatory diseases.

Synthesis of novel 3,5-diaryl pyrazole derivatives using combinatorial chemistry as inhibitors of tyrosinase as well as potent anticancer, anti-inflammatory agents.

In the present article, we have synthesized a combinatorial library of 3,5-diaryl pyrazole derivatives using 8-(2-(hydroxymethyl)-1-methylpyrrolidin-3-yl)-5,7-dimethoxy-2-phenyl-4H-chromen-4-one (1) and hydrazine hydrate in absolute ethyl alcohol under the refluxed conditions. The structures of the compounds were established by IR, (1)H NMR and mass spectral analysis. All the synthesized compounds were evaluated for their anticancer activity against five cell lines (breast cancer cell line, prostate cancer cell line, promyelocytic leukemia cell line, lung cancer cell line, colon cancer cell line) and anti-inflammatory activity against TNF-alpha and IL-6. Out of 15 compounds screened, 2a and 2d exhibited promising anticancer activity (61-73% at 10 microM concentration) against all selected cell lines and IL-6 inhibition (47% and 42% at 10 microM concentration) as in comparison to standard flavopiridol (72-87% inhibition at 0.5 microM) and dexamethasone (85% inhibition at 1 microM concentration), respectively. Cytotoxicity of the compounds checked using CCK-8 cell lines and found to be nontoxic to slightly toxic. Out of 15, four 3,5-diaryl pyrazole derivatives exhibiting potent inhibitory activities against both the monophenolase and diphenolase actions of tyrosinase. The IC(50) values of compounds (2a, 2d, 2h and 2l) for monophenolase inhibition were determined to range between 1.5 and 30 microM. Compounds 2a, 2d, 2h and 2l also inhibited diphenolase significantly with IC(50) values of 29.4, 21.5, 2.84 and 19.6 microM, respectively. All four 3,5-diaryl pyrazole derivatives were active as tyrosinase inhibitors (2a, 2d, 2h and 2l), and belonging to competitive inhibitors. Interestingly, they all manifested simple reversible slow-binding inhibition against diphenolase.

Synthesis and biological evaluation of a novel series of 2,2-bisaminomethylated aurone analogues as anti-inflammatory and antimicrobial agents.

This is the first report on aurones as a new class of drugs with anti-inflammatory and antimicrobial agents. A series of 2,2-bisaminomethylated aurone analogues (4a-j) were synthesized by Mannich reaction from 1,3,5-trimethoxybenzene in three steps. The structures of the newly synthesized compounds were confirmed by IR, (1)H NMR and mass spectral analysis. All the synthesized compounds were screened against the pro-inflammatory cytokines (TNF-alpha, IL-6) and antimicrobial (antibacterial and antifungal) activity. Compounds 4a, 4b, 4c, 4d, and 4e showed promising results against IL-6 at 10 microM concentration (74-100%). Compounds 4a, 4b and 4c were found to be active against TNF-alpha (76-100%) at 10 microM. Interestingly, all compounds have shown good antimicrobial activity. Compounds 4d, 4e and 4f showed excellent antimicrobial activity as compared with standard drugs.

Silica-supported fluoroboric acid (HBF(4)-SiO(2)) catalyzed highly productive synthesis of thiomorpholides as activators of l-asparaginase as well as the antioxidant agent.

An efficient solvent-free procedure for the synthesis of thiomorpholides in the presence of a catalytic amount of solid-supported fluoroboric acid (HBF(4)-SiO(2)) is described. The advantages of this method are high yields, short reaction times, ease of product isolation, low cost, and the catalyst can be recycled for a number of times without significant loss of activity. Three thiomorpholides possessing electron-donating group (4c, 4g, and 4h) were exhibiting excellent stimulatory activities against Erwinia carotovoral-asparaginase. The most potent activator, compound 4h displayed the following kinetic parameters, K(m)=75microM and V(max)=1000micromolmg(-1)min(-1) and K(A)=0.985microM. Furthermore, these compounds (4g, 4h, 4c, 4f, 4a, and 4d) have also shown promising 2,2'-diphenyl-1-picrylhydrazyl (DPPH) reducing antioxidant activity (21-36%) at 1mM concentration as compared to standard butylated hydroxyl anisole (72% at 1mM).