1,4-Naphthoquinone thiazoles: Synthesis, crystal structure, anti-proliferative activity, and inverse molecular docking study

Abstract

In this study, 1,4-naphthoquinone thiazole hybrids were synthesized by reacting 1,4-naphthoquinone thioureas with various α-bromoketones in 78–86 % yields and characterized using 1H NMR, 13C NMR, FT-IR, and HRMS techniques. Furthermore, single crystal x-ray diffraction studies were also performed for 3b and 3c hybrids to determine stereochemistry. Density Functional Theory (DFT) calculations were performed to obtain additional information and to support the x-ray studies. The in vitro anti-proliferative activities of 1,4-naphthoquinone thiazoles were investigated against PC3 human prostate cancer cells. The products 3a–h showed anti-proliferative activity against PC3 cells, and the cell viability studies showed that the IC50 values of compounds 3f and 3e were 20.10 µM and 21.14 µM, respectively, while the other compounds exhibited lesser cytotoxic effects than the former two. Potential target underlying the mechanism of action of the synthesized compounds against prostate cancer was identified using inverse (reverse) docking method. Molecular dynamics simulation was also conducted to confirm the stability of the 3f/enzyme system. It was determined that the solubility in ethanol was better for compounds bearing methyl substituent on X1 location than compounds containing tert‑butyl on the same location. Compounds with F atom on X2 position were more soluble than the others in the corresponding groups.