The penicillincompounds referred to in this specification are generally named with reference to penam (J.Amer.Chem.Soc. 1953, 75, 3293).The cephalosporin compounds according to the invention include compounds of the general formula ##STR4## (wherein A, B, G and R have the above defined meanings, P is an organic group or a hydrogen, chlorine, bromine or fluorine atom) andnon-toxic derivatives there