3D-QSAR and Molecular Docking Approaches for the Identification of Phyto-Inhibitors of Hsp90

Abstract

Inhibition of Hsp90 disrupts the Hsp90 client protein complex, resulting in its breakdown. Phytochemicals from reported anticancer plants were screened against the orthosteric site of Hsp90. The lead compounds were subjected to the Lipinski rule of five to evaluate their drug-likeness. Three-Dimensional Quantitative Structure-Activity Relationships (3D-QSAR), a mathematical model for the inhibition of Hsp90, was also derived. The lead compounds are guaiol from Cannabis sativa, actinidine from Anacadium occidentale, and choline from Tinospora cordifolia with docking scores of -11kcal/mol, -12.1kcal/mol, and -10.8kcal/mol, respectively. The 3D-QSAR model generated is robust and thoroughly validated with a correlation coefficient R of 0.94 and R2 of 0.950. Actinidine, choline and, guaiol are novel and potent inhibitors of Hsp90. They form interactions with key amino acid residues within the Hsp90 orthosteric site.