Antiproliferative Noscapinoids Bearing an Amidothiadiazole Scaffold as Apoptosis Inducers: Design, Synthesis and Molecular Docking.

ABSTRACT

Noscapine an FDA-approved antitussive agent. With low cytotoxicity with higher concentrations, noscapine and its derivatives have been shown to have exceptional anticancer properties against a variety of cancer cell lines. In order to increase its potency, in this study, we synthesized a series of new amido-thiadiazol coupled noscapinoids and tested their cytotoxicity in vitro. All of the newly synthesised compounds demonstrated potent cytotoxic potential, with IC50 values ranging from 2.1 to 61.2 µM than the lead molecule, noscapine (IC50 value ranges from 31 to 65.5 µM) across all cell lines, without affecting normal cells (IC50 value is>300 µM). Molecular docking of all these molecules with tubulin (PDB ID 6Y6D, resolution 2.20 Å) also revealed better binding affinity (docking score range from -5.418 to -9.679 kcal/mol) compared to noscapine (docking score is -5.304 kcal/mol). One of the most promising synthetic derivatives 6aa (IC50 value ranges from 2.5 to 7.3 µM) was found to bind tubulin with the highest binding affinity (ΔGbinding is -28.97 kcal/mol) and induced apoptosis in cancer cells more effectively.