pounds is accomplished by means of a biosynthetic pathway which closely parallels the corresponding pathway to cephalosporin C in Cephalosporium acremonium. Two of the enzymes involved in this pathway, deacetoxycephalosporin C (DAOC) synthetase and DAOC hydroxylase, carry out sequential reactions in which penicillin N undergoes ring expansion to DAOC and then DAOC is hydroxylated at the C3 meth...

The principal cause of bacterial resistance to penicillin and other b-lactam antibiotics is the acquisition of plasmid-encoded b-lactamases, enzymes that catalyze hydrolysis of the b-lactam bond and render these antibiotics inactive. Clavulanic acid is a potent inhibitor of b-lactamases and has proven clinically effective in combating resistant infections. Although clavulanic acid and penicilli...