Two Schiff base ligands L1 and L2 were obtained by the condensation of glycylglycine respectively with imidazole-2-carboxaldehyde and indole-3-carboxaldehyde and their complexes with Zn(II) were prepared and characterized by microanalytical, conductivity measurement, IR, UV-Vis., XRD and SEM. The molar conductance measurement indicates that the Zn(II) complexes are 1 : 1 electrolytes. The IR data demonstrate the tetradentate binding of L1 and tridentate binding of L2. The XRD data show that Zn(II) complexes with L1 and L2 have the crystallite sizes of 53 and 61 nm respectively. The surface morphology of the complexes was studied using SEM. The in vitro biological screening effects of the investigated compounds were tested against the bacterial species Staphylococcus aureus, Escherichia coli, Klebsiella pneumaniae, Proteus vulgaris and Pseudomonas aeruginosa and fungal species Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans by the disc diffusion method. A comparative study of inhibition values of the Schiff base ligands and their complexes indicates that the complexes exhibit higher antimicrobial activity than the free ligands. Zinc ions are proven to be essential for the growth-inhibitor effect. The extent of inhibition appeared to be strongly dependent on the initial cell density and on the growth medium.
Aspergillus flavus ; Aspergillus niger ; Cell Count ; Diffusion ; Electrolytes ; Escherichia coli ; Glycylglycine ; Indoles ; Ions ; Klebsiella ; Ligands ; Mass Screening ; Molar ; Proteus vulgaris ; Pseudomonas aeruginosa ; Rhizoctonia ; Rhizopus ; Schiff Bases ; Staphylococcus aureus ; Zinc

Gamma-glutamyl transpeptidase (GGTP) activity was measured in the homogenate of penile foreskin, using y-glutamyl-p-nitroanilide, as a substrate, and it was found that (GGTP) activity was present in the epidermis and dermis, being more active in the former. The optimum pH for the enzyme was 8.5 - 9.0 in Tris buffer, which was similar to those of the rat kidney and human serum enzymes. It was also revealed that glycylglycine was the most effective activator of the enzyme and some activation was also observed in the presence of L-glutamine. But L-rnethionine, L-homoserine, L-glutamic acid, L-arginine, L-aspartic acid, glycine and L-valine inhibited the activity, suggesting that these amino acids do not act as acceptors of p-glutamyl moiety. The enzyme was remarkably inhibited by bromosulphalein, oxidised gluta,thione, and by L-serine in the presence of borate, and the inhibitions were more severe than is the case with the rat kidney and human serum enzymes.
Amino Acids ; Animals ; Arginine ; Aspartic Acid ; Dermis ; Epidermis ; Foreskin ; gamma-Glutamyltransferase ; Glutamic Acid ; Glutamine ; Glycine ; Glycylglycine ; Humans ; Hydrogen-Ion Concentration ; Kidney ; Patient Acceptance of Health Care ; Rats ; Serine ; Skin* ; Tromethamine ; Valine