Synthesis, spectral characterization, and biological studies of 3,5-disubstituted- 1,3,4-oxadiazole-2(3H)-thione derivatives


Abstract: The reaction of 3,4-dichlorophenyl-1,3,4-oxadiazole-2(3H)-thione with piperidine derivatives via Mannich reaction was used to generate eleven novel compounds in moderate to good yields. Synthesized molecules were characterized according to their structure with 1H NMR, 13C NMR and FT-IR spectral foundations, which were compatible with literature informations. Antimicrobial activity and cytotoxicity studies were done by disc diffusion and NCI-60 sulphordamine B assay methods. The antimicrobial test results revealed that synthesized compounds have better activity against gram-positive species than gram-negative ones. A total analysis of the antibacterial, antifungal, and antiyeast activity revealed that newly synthesized compounds were really active against Bacillus cereus, Bacillus ehimensis, and Bacillus thuringiensis species. For cytotoxicity, among three different cancer cell lines (HCT116, MCF7, HUH7) compounds 5c, 5d, 5e, 5f, 5g, 5i, 5j and 5k were seemed especially effective on HUH7 cancer cell line via moderate to good activity. More significantly, against liver carcinoma cell line (HUH7) most of the compounds of the series (5c-5g and 5i-5j) have better IC50 values (IC50= 18.78 μM) than 5-Florouracil (5-FU) and also compound 5d possessed 10.1 μM value, which represents good druggable cytotoxic activity. Further, the molecules were also screened for in silico chemoinformatic and toxicity data to gather the predicted bioavailibity and safety measurements.

Keywords: 1,3,4-Oxadiazole, piperidine, antibacterial activity, cytotoxicity

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