engleski

Antimicrobial activity of N-phthaloylamino acid-hydroxamates

Antibacterial and antifungal activity of N-phthaloylamino acid-hydroxamates /C6H4(CO)2N-x-CONHOH, x = amino acid residues of glycine, ?-alanine and D-phenylglycine, 1-3 respectively/ was examined against 44 strains of gram-positive and gram-negative bacteria, and 10 species of yeasts. The level of antimicrobial effects was established using in vitro agar assay and standard broth dilution susceptibility test. N-phthaloyl-D-phenylglycine-hydroxamic acid /x = ?CH(Ph)?, 3/, the substance with the highest lipophilicity (log P), showed the best antibacterial activity, especially against gram-negative bacteria. The minimal inhibitory concentration (MIC) of 3 was 0.008 mg/mL in the activity against Yersinia enterocolitica O3, confirmed with a large inhibition zone (30 mm) by diffusion test. Hydroxamates inhibit growth by chelation of metal in PDF enzyme in both, gram (+) and gram (-) bacteria, and LpxC enzyme in gram (-) enzyme. Phthalimides contribute to inhibition likely by destabiling m-RNA. Antifungal activity of the substances 1-3 are not very expressed.

hydroxamic acid; phthalimide; antibacterial activity; PDF and LpxC enzymes; lipophilicity.

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