Synthesis Of Some 2,3-Dihydro-1,3,4-Oxadiazoles And 4,5-Dihydro-1,2,4-Triazoles As Anticancer Agents

Objective: The main objective of this work was to synthesize and evaluate the novel 2,3-dihydro-1,3,4-oxadiazole and 4,5-dihydro-1,2,4-triazole derivatives for cytotoxic activities. Methods: The 2,3-dihydro-1,3,4-oxadiazole derivatives 4a-h were synthesized by cyclization of N'-(substituted-benzylidene) isonicotinohydrazide 3a-e in refluxing acetic anhydride. The 2,3-dihydro-1,3,4-oxadiazole derivatives 4a-h were converted into the corresponding 4,5-dihydro-1,2,4-triazoles 5a-h using ammonia. All the synthesized compounds were identified, depending on the physical and spectral data. Title compounds were assessed for their cytotoxic activity against human cancer cell line (MCF-7) by using Sulforhodamine B (SRB) colorimetric assay. Results: All the synthesized compounds showed characteristic peaks in FTIR, 1HNMR and Mass spectral analysis. The results of the in vitro cytotoxic activity revealed that the compound 4c exhibited equipotent cytotoxic activity with an IC50 value of 8.04 µM when compared with that of standard drug doxorubicin (IC50= 8.02 µM). The reminder compounds have shown good to moderate cytotoxic activities when compared with that of a reference standard. Conclusion: We synthesized a series of title compounds in quantitative yields. Most derivatives showed moderate to good cytotoxic activity.

Biological activity of synthesized 5-{1-[(4-chlorophenyl)sulfonyl]piperidin-4-yl}-2-mercapto-1, 3, 4-oxadiazole derivatives demonstrated by in silico and BSA binding studies

We synthesized a series of compounds bearing pharmacologically important 1,3,4-oxadiazole and piperidine moieties. Spectral data analysis by 1H-NMR, 13C-NMR, IR and EI-MS was used to elucidate the structures of the synthesized molecules. Docking studies explained the different types of interaction of the compounds with amino acids, while bovine serum albumin (BSA) binding interactions showed their pharmacological effectiveness. Antibacterial screening of these compounds demonstrated moderate to strong activity against Salmonella typhi and Bacillus subtilis but only weak to moderate activity against the other three bacterial strains tested. Seven compounds were the most active members as acetyl cholinesterase inhibitors. All the compounds presented displayed strong inhibitory activity against urease. Compounds 7l, 7m, 7n, 7o, 7p, 7r, 7u, 7v, 7x and 7v were highly active, with respective IC50 values of 2.14±0.003, 0.63±0.001, 2.17±0.006, 1.13±0.003, 1.21±0.005, 6.28±0.003, 2.39±0.005, 2.15±0.002, 2.26±0.003 and 2.14±0.002 µM, compared to thiourea, used as the reference standard (IC50 = 21.25±0.15 µM). These new urease inhibitors could replace existing drugs after their evaluation in comprehensive in vivo studies.

Synthesis and antifungal activity of the novel azole compounds / 药学实践杂志

Objective To design and synthesize novel triazole antifungal derivatives with 1 ,3 ,4-oxadiazole side chain for the study of antifungal activities. Methods Fourteen title compounds were synthesized via acylation ,aminolysis reaction ,cy-clization ,nucleophilic substitution ,etc. All the compounds were characterized by 1 H NMR ,MS spectra. The in vitro antifun-gal activities were evaluated against six human pathogenic fungi through the micro-broth dilution method. Results The title compounds exhibited strong antifungal activities against all the tested fungi ,especially against Candida albicans. Compounds 10d ,10i , 10l , and 10n were found to be the most effective , with a minimum inhibitory concentration (MIC80 ) of 0.003 9 μg/ml .They are 16-fold more potent than ICZ ( MIC80 0.062 5 μg/ml) and 64-fold more potent than FCZ (MIC80 0.25 μg/ml) .Conclusion The 1 ,3 ,4-oxadiazole side chain could affect the antifungal activities. That could be due to the prop-er incorporation between the 1 ,3 ,4-oxadiazole substituted phenyl ring with the target enzyme.

Synthesis of some novel enzyme inhibitors and antibacterial agents derived from 5-(1-(4-tosyl)piperidin-4-yl)-1, 3, 4-oxadiazol-2-thiol

ABSTRACT Keeping in mind the pharmacological importance of the 1,3,4-oxadiazole moiety, a series of new S-substituted derivatives, 5a-h, of 5-(1-(4-tosyl)piperidin-4-yl)-1,3,4-oxadiazol-2-thiol (3) were synthesized. The reaction of p-toluenesulfonyl chloride (a) and ethyl isonipecotate (b) produced ethyl 1-(4-tosyl)piperidin-4-carboxylate (1) which was further transformed into 1-(4-tosyl)piperidin-4-carbohydrazide (2) by hydrazine hydrate in methanol. Compound 2 was refluxed with CS2 in the presence of KOH to synthesize 5-(1-(4-tosyl)piperidin-4-yl)-1,3,4-oxadiazol-2-thiol (3). The desired compounds, 5a-h, were synthesized by stirring 3 with aralkyl halides, 4a-h, in DMF using NaH as an activator. The structures of synthesized compounds were elucidated by 1H-NMR, IR and EI-MS spectral studies. These compounds were further evaluated for enzyme inhibitory activity against lipoxygenase and alpha-glucosidase, along with antibacterial activity against Gram-negative and Gram-positive bacteria.

RESUMO Tendo em vista a importância farmacológica da porção 1,3,4-oxadiazol, sintetizou-se uma série de novos derivados S-substituídos, 5a-h, de 5-(1-(4-tosi)piperidin-4-il)-1,3,4-oxadiazol-2-tiol (3). A reação do cloreto de p-toluenossulfonila (a), com isonipecotato de (b) etila forneceu 1-(4-tosil)piperidin-4-carboxilato de metila (1), que foi, em seguida, transformado em 1-(4-tosil)piperidin-4-carbo-hidrazida (2) por reação com hidrato de hidrazina em metanol. O composto 2 foi submetido a refluxo com CS2 na presença de KOH para se obter 5-(1-(4-tosil)piperidin-4-il)-1,3,4-oxadiazol-2-tiol (3). Os compostos desejados, 5a-h, foram obtidos por agitação de 3 com haletos de aralquila, 4a-h, em DMF, na presença de NaH. As estruturas dos compostos sintetizados foram elucidadas através de análise dos espectros de 1H-MNR, IR e EI-MS. Estes compostos foram, ainda, avaliados quanto à inibição das enzimas lipoxigenase e alfa-glucosidase, juntamente com a atividade antibacteriana contra bactérias Gram positivas e Gram negativas.

Synthesis and in vivo Anti-inflammatory and Analgesic activities of Oxadiazoles clubbed with Benzothiazole nucleus.

The aim of the present work is to synthesize and evaluate the anti-inflammatory and analgesic activity of 2-(5-substituted-1,3,4-oxadiazole-2-yl)-1,3-benzathiazole derivatives. In the present investigation, a series of 2-(5-substituted-1,3,4-oxadiazole-2-yl)-1,3-benzathiazole derivatives (3a1-3a9) were synthesized by condensing benzothiazolyl carboxyhydrazide and appropriate aryl acids in the presence of phosphorous oxychloride. Structures of synthesized compounds were established on the basis of IR, 1H NMR, and Mass spectroscopy. All the synthesized compounds were screened for their in-vivo anti-inflammatory and analgesic activities at the dose of 50 mg/kg and 10 mg/kg po. The biological result shows that some compounds were good in their anti-inflammatory and analgesic actions.

Synthesis and in vivo Anti-inflammatory and Analgesic activities of Oxadiazoles clubbed with Benzothiazole nucleus.

The aim of the present work is to synthesize and evaluate the anti-inflammatory and analgesic activity of 2-(5-substituted-1,3,4-oxadiazole-2-yl)-1,3-benzathiazole derivatives. In the present investigation, a series of 2-(5-substituted-1,3,4-oxadiazole-2-yl)-1,3-benzathiazole derivatives (3a1-3a9) were synthesized by condensing benzothiazolyl carboxyhydrazide and appropriate aryl acids in the presence of phosphorous oxychloride. Structures of synthesized compounds were established on the basis of IR, 1H NMR, and Mass spectroscopy. All the synthesized compounds were screened for their in-vivo anti-inflammatory and analgesic activities at the dose of 50 mg/kg and 10 mg/kg po. The biological result shows that some compounds were good in their anti-inflammatory and analgesic actions.