Penicillin and cephalosporin derivatives, processes for their preparation and their applications.

摘要

beta -Lactam compounds of the penicillin and cephalosporin series of the formula IMAGE in which R is a substituent but not hydrogen, E is oxygen or sulphur, B is optionally substituted phenyl, optionally substituted heterocyclyl, cyclohexenyl or cyclohexadienyl, and A is hydrogen, hydroxyl, alkoxy, alkenyloxy or cycloalkoxy, have good antibacterial activity besides excellent tolerability and good solubility, as well as the property of improving the growth and feed conversion of livestock.