Semisynthetic .BETA.-lactam antibiotics. II. Effect on antibacterial activity of ureido N-substituents in the 6-((R)-2-(3-(3,4-dihydroxybenzoyl)-1-ureido)-2-phenylacetamido)penicillanic acids.

Abstract

The synthesis and the relationship between in vitro and in vivo activities of 6-[(R)-2-[3-(3,4-dihydroxybenzoyl)-3-R1-1-ureido]-2- phenylacetamido]penicillanic acids having C2 approximately 8 alkyl or substituted alkyl groups as the substituents (R1) are described. In this series, 6-[(R)-2-[3-(3,4-dihydroxybenzoyl)-3-(3-hydroxypropyl)-1-ureido] -2-phenylacetamido]penicillanic acid (1b, AO-1100) showed the most potent protective effect on mice in experimental Pseudomonas aeruginosa infections, although it did not have the strongest in vitro activity among the penicillins we synthesized.