Investigation of diorganotin(IV) complexes: Synthesis, characterization, in vitro DNA binding studies and cytotoxicity assessment of di-n-butyltin(IV) complex

摘要

Diorganotin(IV) complexes of general formula R2SnL (R = Me, 1; Bu, 2; Ph, 3) with tridentate ONO donor Schiff base ligand were synthesized and structurally characterized by adopting various spectroscopic (IR, H-1 C-13 and Sn-119 NMR, UV-Vis, ESI MS, XRD) and analytical techniques. In vitro DNA binding profile of 1-3 were carried out by various biophysical methods viz., UV-Vis titrations, fluorescence, circular dichroic and viscosity measurements which revealed the electrostatic mode of interaction via phosphodiester backbone of DNA duplex. The intrinsic binding constant K-b values of L and 1-3 were found to be 7.53 x 10(3), 2.98 x 10(4), 5.74 x 10(4) and 3.64 x 10(4) M-1, respectively suggesting the higher binding propensity of 2, di-n-butyltin(IV) complex as compared to 1 and 3. Further, the computer-aided molecular docking technique was carried out to validate and rationalize the observed binding affinities towards the molecular target DNA. The resulting binding energies of docked complexes were found to be -212.2, 317.8 and 286.0 KJ mol(-1), respectively. In addition, complex 2 was found remarkably effective against U373MG (CNS), PC3 (prostrate), Hop62 (lung), HL60 (leukemia), HCT15 (colon), SK-OV-3 (ovarian), HeLa (cervix) and MCF7 (breast) cancer cell lines with GI(50) values <10 mu g/ml. (C) 2014 Elsevier B.V. All rights reserved.