Antiproliferative Activity of Novel Thiopyran Analogs on MCF-7 Breast and HCT-15 Colon Cancer Cells: Synthesis, Cytotoxicity, Cell Cycle Analysis, and DNA-Binding

A series of 6H-thiopyran-2,3-dicarboxylate derivatives 4a-d were synthesized and evaluated for their cytotoxic effect against HCT-15 colon and MCF-7 breast cancer cell lines using Sulforhodamine B (SRB) assay. The results showed that these compounds could exhibit a good cytotoxicity to both cell lines. In addition, these compounds were found to exhibit significant DNA-binding affinity. Ultraviolet-visible light (UV-Vis) spectroscopy was conducted to determine the ability of the ligand under analysis. The effect of ligand complexation on DNA structure led to overall affinity constants of K-4a = 3.5 x 10(4) M-1, K-4b = 6.4 x 10(4) M-1, K-4c = 3.2 x 10(4) M-1, and K-4d = 2.4 x 10(4) M-1. Our findings could provide new evidence showing the relationship between the chemical structure and biological activity and may be useful for the discovery of new anti-cancer drugs.