Publications by authors named "Manjuri Kumar"

We report the synthesis, characterization, anti-cancer activity and mechanism of action of a novel water-soluble Cu(II) complex with salicylidene carbohydrazide as the ligand and -phenanthroline as the co-ligand. The synthesized complex (1) was characterized by FT-IR, EPR, and electronic spectroscopy, as well as single crystal X-ray diffraction. This compound was found to be paramagnetic from EPR spectra and X-ray crystallography revealed that the molecule crystallized in an orthorhombic crystal system.

View Article and Find Full Text PDF

A Cu(II) thiolato complex [CuL()] () (HL = -HOCHC(H)=NCHSH-) and the corresponding water-soluble stable sulfinato-O complex [CuL'()] () (HL' = -HOCHC(H)=NCHS(=O)OH) were synthesized and characterized using physicochemical techniques. Compound is found to be a dimer in the solid state as characterized using single-crystal X-ray crystallography. XPS studies clearly showed the differences in the sulfur oxidation states in and .

View Article and Find Full Text PDF

The isolated copper(II) complex [CuL(-phen)]·HO () [HL = -HO-CHC(H)=N-CH-SH-, -phen = 1,10-phenanthroline] was structurally characterized using single-crystal X-ray crystallography. in CHCN at liquid nitrogen temperature displayed a characteristic monomeric X-band electron paramagnetic resonance spectrum having a tetragonal character with = 2.1479 and = 2.

View Article and Find Full Text PDF

A mononuclear Cu(II) complex [Cu(HL)(-phen)]·HO () [HL =, -phen = 1,10-phenanthroline] was isolated from methanol, and its X-ray single-crystal structure was determined. Frozen glass X-band EPR of in dimethylformamide (DMF) at LNT showed a spectrum that is characteristic of a monomeric tetragonal character with = 2.164, = 2.

View Article and Find Full Text PDF

The interaction of two binuclear mixed ligand Cu(ii) complexes [Cu(o-phen)LCu(OAc)] (1) and [Cu(o-phen)LCu(o-phen)](OAc) (2) (H3L = o-HOC6H4C(H)[double bond, length as m-dash]N-NH-C(OH)[double bond, length as m-dash]N-N[double bond, length as m-dash]C(H)-C6H4OH-o) and a new mononuclear Zn(ii) complex [Zn(HL)(o-phen)(H2O)](OAc)·H2O (3) (H2L = o-HOC6H4-C(H)[double bond, length as m-dash]N-NH-C([double bond, length as m-dash]O)-NH-N[double bond, length as m-dash]C(H)-C6H4OH-o, o-phen = 1,10-phenanthroline, and OAc = CH3COO-) with human serum albumin (HSA) was studied using fluorescence quenching, synchronous and 3D fluorescence measurements and UV-vis spectroscopy. 3D fluorescence studies showed that the HSA structure was altered at the secondary and tertiary levels upon binding with the complexes. This was further supported by the electronic absorption spectral studies of HSA in the absence and presence of the compounds.

View Article and Find Full Text PDF

We report the synthesis, crystal structures and biological activities of two dinuclear Cu(II) complexes [Cu(o-phen)LCu(OAc)] (1) and [Cu(o-phen)LCu(o-phen)](OAc) (2), where o-phen = 1,10-phenanthroline, HL = o-HOCHC(H)=N-NH-C(OH)=N-N=C(H)-CHOH-o, and OAc=CHCOO. Both compounds display strong and broad X-band EPR spectra at RT in their powder state confirming that these are paramagnetic. The intercalative DNA binding of the compounds as revealed from spectrophotometric studies was found to be consistent with the results of fluorescence spectroscopic studies for ethidium bromide displacement assay as well as enhanced viscosity of DNA in the presence of these compounds.

View Article and Find Full Text PDF

We report the biological activity of three Cu(II) complexes [Cu(pabt)Cl] (1), [Cu(pma)Cl] (2), and [Cu(pdta)Cl]Cl (3) (pabt = N-(2-mercaptophenyl)-2'-pyridylmethylenimine, pma = N-(2-pyridylmethyl)-2-mercaptoaniline, pdta = 2,2'-di(pyridyl-2-methyleneimine)diphenyl disulfide). 1-3 display four-line EPR multiplet in solution at RT suggesting that these are mononuclear. DNA-binding studies using spectrophotometric titration of these complexes with calf thymus DNA showed binding through intercalation mode which was found to be consistent with the observation of increased viscosity of DNA and quenching of fluorescence of ethidium bromide bound DNA in the presence of these complexes.

View Article and Find Full Text PDF