Synthesis of New 1, 3, 4-Oxadiazole-Incorporated 1, 2, 3-Triazole Moieties as Potential Anticancer Agents Targeting Thymidylate Synthase and Their Docking Studies

Thymidylate synthase (TS) has emerged as a hot spot in cancer treatment, as it is directly involved in DNA synthesis. In the present article, nine hybrids containing 1,2,3-triazole and 1,3,4-oxadiazole moieties (6–14) were synthesized and evaluated for anticancer and in vitro thymidylate synthase activities. According to in silico pharmacokinetic studies, the synthesized hybrids exhibited good drug likeness properties and bioavailability. The cytotoxicity results indicated that compounds 12 and 13 exhibited remarkable inhibition on the tested Michigan Cancer Foundation (MCF-7) and Human colorectal Carcinoma (HCT-116) cell lines. Compound 12 showed four-fold inhibition to a standard drug, 5-fluoruracil, and comparable inhibition to tamoxifen, whereas compound 13 exerted five-fold activity of tamoxifen and 24-fold activity of 5-fluorouracil for MCF-7 cells. Compounds 12 and 13 inhibited thymidylate synthase enzyme, with an half maximal inhibitory concentration, IC(50) of 2.52 µM and 4.38 µM, while a standard drug, pemetrexed, showed IC(50) = 6.75 µM. The molecular docking data of compounds 12 and 13 were found to be in support of biological activities data. In conclusion, hybrids (12 and 13) may inhibit thymidylate synthase enzyme, which could play a significant role as a chemotherapeutic agent.