cephalosporins possessing a 1 , 3-dithiolane , 1 , 3-dithiane , or 1 , 3-dithietane ring on their 7 beta-substituents showed potent inhibitory activity against cephaloridine hydrolysis by cephalosporinases purified from proteus morganii , proteus rettgeri , and proteus inconstans , which were not inhibited by clavulanic acid , a well-known beta-lactamase inhibitor .
C3536856
cephalosporins
C0007727
cephaloridine