Antibacterial penicillins of the formula ##STR1## or a pharmaceutically acceptable salt thereof wherein R.sup.1 is a heterocyclic group and R is hydrogen, the residue of certian carboxy protecting groups or the residue of an ester group readily hydrolyzable in vivo having activity against resistant organisms.
公式为##STR1##的抗菌
青霉素,或其药学上可接受的盐,其中R.sup.1是杂环基团,R是氢,某些羧保护基团的残基或易在体内
水解的酯基团的残基,具有对抗耐药菌的活性。