Synthesis, characterization, and DNA damaging of bivalent metal complexes incorporating tetradentate dinitrogen–dioxygen ligand as potential biocidal agents

Synthesis Characterization and Biological Activities of Coordination Compounds of 4-Hydroxy-3-nitro-2H-chromen-2-one and Its Aminoethanoic Acid and Pyrrolidine-2-carboxylic Acid Mixed Ligand Complexes

Coordination compounds of 4-hydroxy-3-nitro-2H-chromen-2-one and their mixed ligand complexes with aminoethanoic acid and pyrrolidine-2-carboxylic acid were synthesized by the reaction of Cu(II) and Zn(II) salts in molar ratio 1 : 2 for the coumarin complexes and 1 : 1 : 1 for the mixed ligand complexes, in basic media. The compounds formed were characterized using infrared, Uv-vis spectrophotometric analyses, mass spectrometry, magnetic susceptibility measurements, and EDX analyses. It was concluded that 4-hydroxy-3-nitro-2H-chromen-2-one coordinated as a monobasic ligand for all the complexes; it also coordinated via the carbonyl moiety in the case of the Cu(II) mixed ligand complexes. Similarly it was proposed that the amino acids also coordinated in a bidentate fashion via their amino nitrogen and carboxylate oxygen atoms. The synthesized compounds were screened for their antimicrobial and cytotoxic activities. The complexes exhibited marginal antimicrobial activity but good cytotoxic activity.

Syntheses, Characterization, Resolution, and Biological Studies of Coordination Compounds of Aspartic Acid and Glycine

Enantiomerically enriched coordination compounds of aspartic acid and racemic mixtures of coordination compounds of glycine metal-ligand ratio 1 : 3 were synthesized and characterized using infrared and UV-Vis spectrophotometric techniques and magnetic susceptibility measurements. Five of the complexes were resolved using (+)-cis-dichlorobis(ethylenediamine)cobalt(III) chloride, (+)-bis(glycinato)(1,10-phenanthroline)cobalt(III) chloride, and (+)-tris(1,10-phenanthroline)nickel(II) chloride as resolving agents. The antimicrobial and cytotoxic activities of these complexes were then determined. The results obtained indicated that aspartic acid and glycine coordinated in a bidentate fashion. The enantiomeric purity of the compounds was in the range of 22.10–32.10%, with (+)-cis-dichlorobis(ethylenediamine)cobalt(III) complex as the more efficient resolving agent. The resolved complexes exhibited better activity in some cases compared to the parent complexes for both biological activities. It was therefore inferred that although the increase in the lipophilicity of the complexes may assist in the permeability of the complexes through the cell membrane of the pathogens, the enantiomeric purity of the complexes is also of importance in their activity as antimicrobial and cytotoxic agents.

Synthesis, Characterization, and Antimicrobial Activities of Coordination Compounds of Aspartic Acid

Coordination compounds of aspartic acid were synthesized in basic and acidic media, with metal ligand M : L stoichiometric ratio 1 : 2. The complexes were characterized using infrared, electronic and magnetic susceptibility measurements, and mass spectrometry. Antimicrobial activity of the compounds was determined against three Gram-positive and three Gram-negative bacteria and one fungus. The results obtained indicated that the availability of donor atoms used for coordination was a function of the pH of the solution in which the reaction was carried out. This resulted in varying geometrical structures for the complexes. The compounds exhibited a broad spectrum of activity and in some cases better activity than the standard.

Transition metal complexes of symmetrical and asymmetrical Schiff bases as antibacterial, antifungal, antioxidant, and anticancer agents: progress and prospects

The huge research on Schiff base coordination complexes in the past few decades has given rise to several new molecules that have been of biological importance. The ease with which the Schiff base ligands are designed and prepared and their pattern is elucidated have made them to be referred to as “fortunate ligands” possessing azomethine derivatives, the C=N linkage that is essential for biological activity, including antibacterial, antifungal, antioxidant, anticancer, and diuretic activities. A variety of Schiff base and its complexes have been studied as model molecules for biological oxygen carrier systems. The uses of Schiff bases as DNA-cleaving agents and its mode of interaction and free-radical scavenging properties are described. The review encapsulates the applications of Schiff bases and their complexes.

Bis-amide transition metal complexes: isomerism and DNA interaction study

A quatridentate bis-amide ligand, N,N'-propylenebis(salicylamide) H2pbs, and its transition metal complexes [M(pbs)(H2O)2], where M=Co(II), Ni(II), Cu(II), and Zn(II) have been synthesized and characterized by elemental analysis, UV-Vis, IR, NMR, Mass, EPR, molar conductivity, magnetic moment values and thermal analysis. The NMR spectrum of ligand evidences the E/Z isomerism. All the evidences reveal that the metal ions adopt octahedral geometry with metal:ligand:solvent ratio 1:1:2. The conductivity measurements exhibit that the complexes are non-electrolytes. DNA binding properties of these complexes have been explored by UV-Vis and cyclic voltammetry. The results indicate that these complexes are good intercalators.