Synthesis and microbiological activity of some N-(o-hydroxyphenyl)benzamides and phenylacetamides as the possible metabolites of antimicrobial activebenzoxazoles: Part II

The synthesis of some N-(o-hydroxyphenyl)benzamides and benzacetamides (2a- 2p) in order to determine their in vitro antimicrobial activity against two Gram-positive bacteria, three Gram-negative bacteria and the fungus Candid a albicans is described. The new compounds were compared with several contr ol drugs. The derivative 2g, 4-amino-N-(o-hydroxyphenyl)benzamide, was foun d active at an MIC value of 25 mug/ml against the Gram-negative microorgani sm Klebsiella pneumoniae. Most of the compounds exhibited antibacterial act ivity at an MIC value of 25 mug/ml against Pseudomonas aureginosa. For the antifungal activity against C. albicans, compounds 2e, 2h and 2m were found more active than the other derivatives (MIC 12.5 mug/ml). The antimicrobia l activity of some of these benzamide and phenylacetamide derivatives (2a, 2b, 2f, 2g, 2h and 2k), possible metabolites of benzoxazoles, was also comp ared with that of the cyclic analogues 3-8. Compound 2f possesses two dilut ions better antifungal activity than its cyclic analogue the benzoxazole de rivative 5 against C. albicans, while having one dilution better antibacter ial activity against Streptococcus faecalis and K. pneumoniae. (C) 2000 Els evier Science S.A. All rights reserved.