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Diorganotin(IV) complexes 1-3 (R ¼ Me, 1; Bu, 2; Ph, 3) derived from the ligand N 0 -(4-hydroxypent-3-en-2ylidene)isonicotinohydrazide were synthesized and thoroughly characterized by elemental analysis and spectroscopic techniques (UV-vis, IR, 1 H, 13 C and 119 Sn NMR and ESI-MS). The molecular structure of diphenyltin(IV) complex 3 was further established by single crystal X-ray crystallography which showed that the complex crystallized in the monoclinic space group C21/c. To ascertain the pharmacokinetic and chemotherapeutic aspects of the synthesized diorganotin(IV) complexes 1-3, in vitro interaction studies were carried out with CT DNA/HSA by employing various biophysical methods viz., UV-vis, fluorescence, FT IR (in case of HSA only) and circular dichroism. Notably, all of the complexes exhibited a high propensity for DNA binding via electrostatic modes; the binding affinity was found to be in the order 2 > 3 > 1 and also revealed static quenching of the HSA fluorophore. The experimental findings were validated by density functional theory (DFT) calculations which determined the quantum mechanical (QM) reactivity descriptors viz., single point energy (H), hardness (h), electronic chemical potential (m), electrophilicity (u); on that basis the binding trend of the complexes with CT DNA and HSA could be predicted. Further, molecular docking studies were performed to visualize the preferential binding sites of diorganotin(IV) complexes with DNA and HSA. In vitro cytotoxicity of di-n-butyltin(IV) complex 2 was carried out in a panel of human cancer cell lines viz., U373MG (CNS), PC3 (prostrate), Hop62 (lung), HL60 (leukemia), HCT15 (colon), SK-OV-3 (ovarian), HeLa (cervix) and MCF7 (breast) which revealed significantly good activity with GI 50 values of <10 mg mL À1 for most of the cell lines tested.

Dimethyltin(IV) complexes with ethanolamine (1) and biologically significant N-glycosides (2 and 3) were designed and synthesized. The structural elucidation of complexes 1-3 was done using elemental and spectroscopic methods; in addition, complex 1 was studied by single crystal X-ray diffraction studies. The in vitro DNA binding profile of complexes 2 and 3 was carried out by employing different biophysical methods to ascertain the feasibility of glycosylated complexes. Further, the cleaving ability of 2 and 3 was investigated by the agarose gel electrophoretic mobility assay with supercoiled pBR322 DNA, and demonstrated significantly good nuclease activity. Furthermore, both the complexes exhibited significant inhibitory effects on the catalytic activity of human Topo I at lower concentration than standard drugs. Computer-aided molecular docking techniques were used to ascertain the mode and mechanism of action towards the molecular target DNA and Topo I. The cytotoxicity of 2 and 3 against human hepatoma cancer cells (Huh7) was evaluated, which revealed significant regression in cancerous cells as compared with the standard drug. The antiproliferative activities of 2 and 3 were tested against human hepatoma cancer cells (Huh7), and results showed significantly good activity. Additionally, to validate the remarkable antiproliferative activity of complexes 2 and 3, specific regulatory gene expression (MMP-2 and TGF-β) was obtained by real time PCR.

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