Synthesis and structural characterization of the novel copper complex, DFT based vibrational analysis, DNA binding studies. In vitro cytotoxicity against A549 cancer cell lines and estimation of GSH, ROS, LPO levels, have been reported.

New copper(I) complexes [CuCl(PPh3)(L)] (1: L = LA = 4-carboxyphenyl)bis(3,5-dimethylpyrazolyl)methane; (2: L = LB = 3-carboxyphenyl)bis(3,5-dimethylpyrazolyl)methane) were prepared and characterised by elemental analysis and various spectroscopic techniques such as FT-IR, NMR, UV–Vis, and ESI-MS. The molecular structures of complexes 1 and 2 were analyzed by theoretical B3LYP/DFT method. Furthermore, in vitro DNA binding studies were carried out to check the ability of complexes 1 and 2 to interact with native calf thymus DNA (CT-DNA) using absorption titration, fluorescence quenching and circular dichroism, which is indicative of more avid binding of the complex 1. Moreover, DNA mobility assay was also conducted to study the concentration-dependent cleavage pattern of pBR322 DNA by complex 1, and the role of ROS species to have a mechanistic insight on the cleavage pattern, which ascertained substantial roles by both hydrolytic and oxidative pathways. Additionally, we analyzed the potential of the interaction of complex 1 with DNA and enzyme (Topo I and II) with the aid of molecular modeling. Furthermore, cytotoxic activity of complex 1 was tested against HepG2 cancer cell lines. Thus, the potential of the complex 1 is promising though further in vivo investigations may be required before subjecting it to clinical trials.

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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.

The problem of a cylindrical mixture of a nonlinearly elastic solid and an ideal fluid subjected to combined finite axial extension and torsion is considered. In previous work, a 'universal relation' has been presented by assuming a small angle of twist. In this work, the general problem for the finite deformation of the swollen cylinder is discussed in the context of Mixture Theory. ComputationAl results for the variation of the radial and tangential streLeh ratios and the distribution of the fluid in the swollen deformed state are presented. The results demonstl'a~e that the swollen volume of a cylinder reduces wi~h twisting when the axial stretch ratio is held constant. Computational results for the reduction in the swollen volume predict the same qualitative and quantitative trends as observed in experimental results.

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Spin coupling models are different between iron and manganese in their dication diradical complexes, which is reflected in their reactivity as shown.