Synthesis, Antiproliferative and Antioxidant Activity of 3-Mercapto-1,2,4-Triazole Derivatives as Combretastatin A-4 Analogues

Two series of 3-mercapto-1,2,4-triazole derivatives containing alkoxy substituents different in size and position were synthesized and their structures were characterized by FT-IR, H-1 NMR, C-13 NMR spectroscopy and elemental analysis. The synthesized compounds were assessed for their antiproliferative activity against colon cancer cell line (SW480). The results indicated that the size and position of the alkoxy group significantly influenced the antiproliferative activity. The highest cancer cell growth inhibition values were observed for the compounds containing 3,4,5-trimethoxyphenyl groups in their structures (57.74, 54.14 and 60.70% at 50 mu M for compounds 5a, 12b and 14, respectively). The synthesized compounds were also subjected to DPPH protocol for evaluating the antioxidant activity. The results showed that all compounds had moderate to high levels of antioxidant capacity as compared to ascorbic acid as standard, the highest free radical scavenging capacity of 75% was observed for compound 4a at 50 mu M.