Prashant K. Sharma

Superoxide scavenging and antimicrobial activities of novel transition metal complexes of oxydiacetate dianion as primary ligand: spectral characterization, cyclic voltammetric investigations and crystal structure.

Complexes of stoichiometries [M(oda)(4-pic)H(2)O]·xH(2)O [M = Cu(1), x = 2; Co (2), x = 4; Ni (3), x = 2; ] [Fe(oda)(4-pic)]·Cl (4) and {[Cu(2-pa)(2)]·2H(2)O}(n) (5) (H(2)oda = oxydiacetic acid, 4-pic = 4-picoline and 2-paH = 2-picolinic acid) were prepared to explore their uses as possible models for mono- and poly-nuclear metallo-pharmaceuticals. The chemical structures were elucidated by IR, FAB-Mass, (1)H, (13)C NMR, EPR and UV-visible (ligand field) spectral analyses. Electrochemical investigations are consistent with formation of stable quasi-reversible redox Co(II/III) and Cu(II/III) couples in the solution. Single crystal X-ray data of the complex (5) indicated a 1D coordination polymeric structure with extensive H-bonding to form supramolecular frameworks. The antimicrobial activities were examined against Escherichia coli (k-12), Bacillus subtilis (MTC-121), Staphylococcus aureus (IOASA-22), Salmonella typhimurium (MTCC-98), Candida albicans, Aspergillus fumigatus and Penicillium marneffei. The superoxide dismutase (SOD) activities of the Cu(II) complexes (1 and 5) were assessed employing nitrobluetetrazolium (NBT) assay.

Isolation of a Decavanadate Cluster [H2V10O28][4-picH]4·2H2O (4-pic = 4-picoline): Crystal Structure, Electrochemical Characterization, Genotoxic and Antimicrobial Studies

The studies on polyoxovanadate clusters have received considerable attentions due to their interesting structures and extensive applications in material science and medicinal chemistry. A novel decavanadate cluster with composition [H2V10O28][4-pic]4·2H2O has been synthesized in aqueous solution and characterized by spectral (FTIR, 51V NMR, EPR and Mass) and electrochemical studies. Single crystal X-ray crystallographic investigations indicate that decavanadate anion [H2V10O28]4− and the protonated counter cations (4-picH+) stabilize the crystal lattice giving a 2D sheet consolidated via extensive H-bonding interactions. Cyclic voltammetric studies indicate formation of stable quasi-reversible redox couple

Synthesis, spectral characterizations and biological studies of transition metal mixed ligand complexes: X-ray crystal structures of [Cu(oda)(Bipy)(H2O)]·4H2O and [VO(oda)(Bipy)]·2H2O

\left( {{\text{V}}^{\text{V}} \overset {} \rightleftharpoons {\text{V}}^{\text{IV}} } \right)

Structural, electrochemical characterization and SOD mimic activities of 1D chain or 3D network encouraged by unique μ2-bridging by adipate ion in mixed ligand complexes containing α-diimine as auxiliary ligand

VV⇌VIV in solution. The genotoxic studies employing single cell gel electrophoresis and plasmid nicking assay ascertained the non toxic nature of the compound. The complex has also been tested for in vitro antimicrobial activities against gram +ve and gram −ve bacteria and fungi. The compound can thus be exploited as antimicrobial agent since it does not cause any toxicity or damage to DNA.

Synthesis, structural characterization, DNA binding studies and antitumor properties of tin(II)-oxydiacetate complexes containing α-diimine as auxiliary ligand.

Abstract Dinuclear tin(IV) dicarboxylate complexes of the types [(n-Bu)2Sn(oda)(4-pic)]2·2H2O (1) and [(n-Bu)2Sn(pda)(H2O)]2 (2) [H2oda = oxydiacetic acid; H2pda = pyridine 2,6-dicarboxylic acid) were synthesized and characterized via physicochemical and spectroscopic studies. The spectroscopic results indicated that Sn is seven-coordinate having pentagonal bipyramidal (pbp) geometry in both complexes. The X-ray study of complex 2 further specified pentagonal bipyramidal geometry with dinuclear structural arrangement due to the involvement of carboxylate bridges formed by pda2− moiety. The crystal structure is further stabilized by different weak interactions viz., C–C⋯H, C–C⋯O, C–H⋯O, C–C⋯O, and C–H⋯H. These interactions are further supported by Hirshfeld surface analysis along with 2-D fingerprint plots of complex 2. In vitro DNA-binding studies of both complexes were evaluated using spectroscopic techniques (absorbance and fluorescence) which ascertained optimum binding affinity of both complexes. However, cleavage activity of the complexes was assessed using supercoiled DNA (pBR322) via gel electrophoresis technique which demonstrated significant cleavage pattern of both complexes at different concentrations. Furthermore, chemotherapeutic potential of complexes 1 and 2 against MCF-7 and Hep carcinoma cell lines also suggested significant antiproliferative effect of complexes. These results revealed momentous exploration of drug–DNA interactions which may engender new insinuation for the advancement of metallo-pharmaceuticals.