Synthesis, Characterisation and Biological Role of Anions (Nitrate, Sulphate, Oxalate and Acetate) in Co(II), Cu(II) and Ni(II) Metal Chelates of Some Schiff Base Derived Amino Acids

Synthesis, spectral characterization and DNA binding of Schiff-base metal complexes derived from 2-amino-3-hydroxyprobanoic acid and acetylacetone

Four new metal complexes derived from the reaction of Cu(II), Co(II), Ni(II) and Zn(II) acetates with the Schiff-base ligand (H3L) resulted from the condensation of the amino acid 2-amino-3-hydroxyprobanoic acid (serine) and acetylacetone have been synthesized and characterized by, elemental analyses, ES-MS, IR, UV-Vis., 1H NMR, 13C NMR, ESR, thermal analyses (TGA and DTG) and magnetic measurements. The results showed that the Schiff-base ligand acts as bi-negative tridentate through the azomethine nitrogen, the deprotonated carboxylate oxygen and the enolic carbonyl oxygen. The optical band gaps measurements indicated the semi-conducting nature of these complexes. Molecular docking was used to predict the binding between the Schiff base ligand with the receptor of prostate cancer mutant H874Y. The interactions between the Cu(II) complex and calf thymus DNA (CT-DNA) have been studied by UV spectra. The results confirm that the Cu(II) complex binds to CT-DNA in an intercalative mode.

Synthesis characterization and antimicrobial activity studies of some transition metal complexes derived from 3-chloro-N'-[(1E)-(2-hydroxy phenyl)methylene]-6-methoxy-1-benzothiophene-2-carbohydrazide

A series of new coordination complexes of Cu(II), Co(II), Ni(II), Zn(II), Hg(II), Mn(II), and Fe(III) with the Schiff base 3-chloro-N'-[(1E)-(2-hydroxy phenyl)methylene]-6-methoxy-1-benzothiophene-2-carbohydrazide (HL) have been synthesized and characterized by elemental analysis, electrical conductivity measurements, IR spectra, (1)H NMR, mass spectral data, electronic spectra, magnetic susceptibility, ESR spectra, TGA, and Powder XRD data. The Schiff base behaves as tridentate ONO donor ligand and forms the complexes of the type ML2 (metal-ligand) stoichiometry for Cu(II), Co(II), Ni(II), and Mn(II) complexes and ML stoichiometry for Zn(II), Hg(II), and Fe(III) complexes. All the complexes are colored and nonelectrolytes. It is found that Cu(II), Co(II), Ni(II), Mn(II) and Fe(III) complexes have exhibited octahedral geometry whereas Zn(II) and Hg(II) complexes exhibited tetrahedral geometry. The ligand and its metal complexes have been screened for their antibacterial activity against E. coli and S. aureus and antifungal activity against A. niger and A. flavus.

Bis[μ-N-(3-meth-oxy-2-oxidobenzyl-idene-1:2κ(2)O(2):O(2))-l-isoleucinato-2κ(2)N,O]bis-(1,10-phenanthroline-1κ(2)N,N')dinickel(II) methanol tetra-solvate trihydrate

In the title complex, [Ni₂(C₁₄H₁₇NO₄)₂(C₁₂H₈N₂)₂]·4CH₃OH·3H₂O, the two Ni^II ions are bridged by two Schiff base anions, leading to a dinuclear complex. One Ni^II ion is six-coordinated by four O atoms and two N atoms of two tridentate Schiff base ligands derived from the condensation of l-isoleucine and o-vanillin. The other Ni^II ion is six-coordinated by four N atoms of two 1,10-phenanthroline ligands and two O atoms of the Schiff base ligands. In the crystal, inter­molecular O—H⋯O and C—H⋯O hydrogen bonds lead to a three-dimensional structure. Intra­molecular C—H⋯O hydrogen bonds are also present. One of the methyl groups of the l-isoleucinate moieties is disordered over two sets of sites with an occupancy ratio of 0.687 (19):0.313 (19) and two methanol mol­ecules are half-occupied.

Synthesis, characterization and biological studies of sulfonamide Schiff's bases and some of their metal derivatives

A new series of Schiff base ligands derived from sulfonamide and their metal(II) complexes [cobalt(II), copper(II), nickel(II) and zinc(II)] have been synthesized and characterized. The nature of bonding and structure of all the synthesized compounds has been explored by physical, analytical and spectral data of the ligands and their metal(II) complexes. The authors suggest that all the prepared complexes possess an octahedral geometry. The ligands and metal(II) complexes have been screened for their in vitro antibacterial activity against bacterial strains, Escherichia coli, Shigella flexneri, Pseudomonas aeruginosa, Salmonella typhi and for antifungal activity against fungal strains, Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glabrata. These assays enabled the identification of the metal complexes as an effective antimicrobial agent with low cytotoxicity.

[N-(3-Meth-oxy-2-oxidobenzyl-idene-κO)threoninato-κO,N](1,10-phenanthroline-κN,N')copper(II) hemihydrate

In the title complex, [Cu(C(12)H(13)NO(5))(C(12)H(8)N(2))]·0.5H(2)O, the Cu(II) ion is five-coordinated by one N atom and two O atoms from a tridentate Schiff base ligand, derived from the condensation of l-threonine and o-vanillin, and two N atoms from a 1,10-phenanthroline ligand in a distorted square-pyramidal geometry. In the crystal, inter-molecular O-H⋯O hydrogen bonds form a one-dimensional left-handed helical structureextending parallel to [001]. The water molecule of crystallization shows half-occupancy.

{2-(4-Hy-droxy-phen-yl)-2-[(3-meth-oxy-2-oxidobenzyl-idene)amino-κO,N]propanoato-κO}(1,10-phenanthroline-κN,N')copper(II) dihydrate

In the title complex, [Cu(C(17)H(15)NO(5))(C(12)H(8)N(2))]·2H(2)O, the central Cu(II) ion is five-coordinate, bound to one N atom and two O atoms from the Schiff base ligand and by two N atoms from a 1,10-phenanthroline ligand in a distorted square-pyramidal configuration. In the crystal, inter-molecular O-H⋯O and C-H⋯O hydrogen bonds form a two-dimensional network parallel to (001).

Transition metal complexes of a new hexadentate macroacyclic N2O4-donor Schiff base: inhibitory activity against bacteria and fungi

A new hexadentate macroacyclic N(2)O(4) - donor ligand, glyoxal bis(N-nitroso phenylglycine) (gbnp), has been designed and structurally characterized. Manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes of gbnp have been prepared and characterized by elemental analyses, molar conductance measurements, magnetic moment, spectral (IR, (1)H NMR, electronic and FAB mass) and thermal studies. The molecular dynamics of the ligand was studied by the variable temperature NMR studies, which suggest the presence of two isomeric forms. The antimicrobial activity of all the compounds was studied against Escherichia coli, Bacillus cirroflagellosus, Aspergillus niger and Candida albicans. Among the new complexes, copper(II) complex has the highest potential against all the microorganisms tested.

Metal-based sulfonamides: their preparation, characterization and in-vitro antibacterial, antifungal & cytotoxic properties. X-ray structure of 4-[(2-hydroxybenzylidene) amino] benzenesulfonamide

Synthesis, characterization and biological studies of Schiff base-derived sulfonamides and their Co (II), Cu (II), Ni (II) and Zn (II) complexes have been reported and screened for in-vitro antibacterial activity against six Gram-negative; E. coli, K. pneumoniae, P. aeruginosa, P. mirabilis, S. typhi and S. dysenteriae and four Gram-positive; B. cereus, C. diphtheriae, S. aureus and S. pyogenes bacterial strains and for in-vitro antifungal activity against T. longifusus, C. albicans, A. flavus, M. canis, F. solani, and C. glaberata. All compounds showed moderate to significant antibacterial activity, however, the zinc (II) complexes were found to be more active. Some of the compounds also showed significant antifungal activity against various fungal strains. Only compounds (6) and (10) displayed potent cytotoxic activity with LD(50) = 4.644 x 10(- 4) and 4.106 x 10(- 4) moles/mL respectively, against Artemia salina. The X-ray structure of 4-[(2-hydroxybenzylidene)amino]benzenesulfonamide is also reported.