Preparation, antimicrobial activity, and toxicity of 2-amino-4-arylthiazole derivatives

Abstract

Seven 2-amino-4-aryl-1,3-thiazoles (1a-g) and their corresponding 2-aminoacetyl (2a-g) and 2-aminoacetyl-5-bromo (3a-g) derivatives were synthesized and tested in vitro against 11 reference strains, three Gram-positive and four Gram-negative bacteria, two yeasts, and two moulds. Toxicity of the compounds was also evaluated using the brine shrimp test. Compounds 1a, 1b, 1e-g, and 3b showed moderate antimicrobial activity at different concentrations. The results indicated that acetylation of the amino group and bromination at position 5 of the thiazole moiety cause lost of activity. Compounds 1a, 1e, and 1f showed toxicity to brine shrimp nauplii below 10 ppm. Most other compounds showed moderate toxicity, LD50 above 100 ppm. Structures of all compounds were confirmed by NMR and MS data. © 2006 Wiley Periodicals, Inc.