| abstract |
2-Hetero-acetamido-penicillanates and cephalosporinates of the formula <IMAGE> in which R is hydrogen or lower alkoxy, Z is <IMAGE> R1 and R 2 independently or together are various radicals, A is -CH2-CH2-,-CH2-CH2-CH2- or <IMAGE> n is 1 or 2, X is S,O,SO,SO2 or -CH2-, Y is the balance of a penicillin or cephalosporin moiety, and B is a heterocyclic radical, in the form of the acid, a hydrate thereof, a salt thereof or a salt of the hydrate, exhibit marked anti-bacterial properties rendering them suited for use as antibiotics and animal feed supplements. |