De novo design of chiral organotin cancer drug candidates: Validation of enantiopreferential binding to molecular target DNA and 5′-GMP by UV-visible, fluorescence, 1H and 31P NMR

N,N-bis[(R-/S-)-1-benzyl-2-ethoxyethane] tin (IV) complexes were synthesized by applying de novo design strategy by the condensation reaction of (R-/S-)2-amino-2-phenylethanol and dibromoethane in presence of dimethyltin dichloride and thoroughly characterized by elemental analysis, conductivity measurements, IR, ESI-MS, H-1, C-13 and Sn-119, multinuclear NMR spectroscopy and XRD study. Enantioselective and specific binding profile of R-enantiomer 1 in comparison to S-enantiomer 2 with ultimate molecular target CT-DNA was validated by UV-visible, fluorescence, circular dichroism, H-1 and P-31 NMR techniques. This was further corroborated well by interaction of 1 and 2 with 5'-GMP. (C) 2011 Elsevier B.V. All rights reserved.