Akademik Veri Yönetim Sistemi
International Journal of Pharmaceutics, cilt.110, sa.2, ss.109-115, 1994 (SCI-Expanded)
The synthesis and in vitro antimicrobial activity of 5-substituted 2-(3-pyridyl)benzoxazoles (3-7) is described for some Gram-positive and Gram-negative bacteria and the yeast Candida albicans. The compounds 3-7 exhibited significant activity against the screened microorganisms, having MIC values between 25 and 12.5 μg/ml. Quantum-chemical calculations were performed for the compounds 1-10, in order to observe some feasible structure-activity relationships. These theoretical observations, calculated for the description of the mechanism of interactions at the molecular level, revealed that the electrophilic superdelocalizability of the nitrogen atom (SNE) in the oxazolo moiety of the benzoxazole ring is related to the activity. The results obtained from the theoretical calculations and the observed MIC values show that 2-(3-pyridyl)- and 2-phenylbenzoxazole derivatives exhibit bio-isosteric effects for antimicrobial activity. Additionally, substituents at position 5 on the fused heterocyclic system contribute to the activity constructively or destructively depending on the type of microorganism screened. © 1994.