| abstract |
New alpha-acylamino- and alpha-thioacylamino lactam derivs. are cpds.of formula (I) (where A is an opt. branched 2-10C bivalent radical, opt. substd. by aryl, aralkyl, cycloalkyl or halogen, which may form part of a carbocyclic system and/or interrupted by O, opt.substd. N or S; X and Y are O or S; R1 and R2 are H or opt.substd. alkyl, allyl, propargyl, cycloalkyl, aralkyl or aryl; R3 is alkyl or opt. substd. allyl, propargyl, cycloalkyl, aryl or heterocyclyl when X and Y are both O, or is opt. substd. alkyl, allyl, propargyl, cycloalkyl, aralkyl, aryl or heterocyclyl, or a salt-forming cation when at least one of X and Y is S). (I) have antimicrobial activity, and may be used in medicine, as growth promoting and feed utilization improving agents in animals, and as preservatives. (I) show strong antibacterial activity against both gram-positive and gram-negative organisms. When administered orally and subcutaneously to mice, the excreted urine has strong antibacterial activity. |