6β-((R)-2,2-dimethyl-3-nitroso-5-oxo-4-phenyl-imidazolidin-1-yl)-1ξ-oxo-1λ4-penicillanic acid
6β-((R)-2,2-dimethyl-3-nitroso-5-oxo-4-phenyl-imidazolidin-1-yl)-penicillanic acid
hetacillin
cefalexin
(6R,7R,4'R)-7-(2',2'-dimethyl-3'-nitroso-5'-oxo-4'-phenylimidazolidin-1'-yl)-3-methylceph-3-em-4-carboxylate