Antimicrobial activities of N-(2-hydroxy-1-naphthalidene)-amino acid(glycine, alanine, phenylalanine, histidine, tryptophane) Schiff bases and their manganese(III) complexes

The in vitro antibacterial and antifungal activities of five different amino acid Schiff bases derived from the reaction of 2-hydroxy-1-naphthaldehyde with glycine, L-alanine L-phenylalanine, L-histidine, L-tryptophane and the manganese(III) complexes of these bases were investigated. Structures of the Schiff bases were proven by 1H-NMR. In vitro activities against some Gram-positive (Staphylococcus aureus and Bacillus polymyxa) and Gram-negative (Escherichia coli) bacteria and the fungus Candida albicans were determined. The antimicrobial activities tended to decrease with the increasing size of the amino acid residues.