Disclosed are compounds of the general formula: ##STR1## wherein R.sup.1 is a hydrogen atom or a lower alkyl group and R.sup.2 is a hydrogen atom or an ester residue, said derivative having the (3S,4S)-configuration; and pharmaceutically acceptable salts and esters thereof. The compounds have antimicrobial and/or .beta.-lactamase-inhibitory activity and are of value as drugs for human beings and domesticated animals.
揭示的是一般式为:##STR1##的化合物,其中R.sup.1是氢原子或较低的烷基基团,R.sup.2是氢原子或酯基团,所述衍
生物具有(3S,4S)-构型;以及其药学上可接受的盐和酯。这些化合物具有抗微
生物和/或β-内酰胺酶抑制活性,并且作为人类和驯养动物的药物具有价值。