Conformational characteristics decisive for their biological action of organotin metallotherapeutics using a combination of NMR methods and in silico calculations

This study involves the structure elucidation and conformational analysis of three synthetic metallotherapeutics organotin (IV) derivatives of cholic acid (CAH) with the formulate R3Sn(CA) (R= Ph- (1), n-Bu- (2)) and R2Sn(CA)2 (R= Me- (3). The structures of compounds (1-3) were assigned using a combination of homonuclear and heteronuclear 2D NMR experiments. Subsequently, 119Sn NMR experiments and semi-empirical quantum mechanic computations (method PM6) were applied to determine the geometry surrounding the tin atom. Results showed that their optimized geometry is distorted tetrahedral and thus their biological activity of these compounds may be related with the conformation of atoms which endue the metal of Sn. In silico molecular docking studies were performed to the ER-α (estrogen receptor alpha ligand) justifying the compounds’ biological activity.