sodium 6β-<(D)-2-(4-ethyl-2,3-dioxopiperazin-1-ylcarbonylamino)-2-(3,4-diacetoxyphenyl)acetamido>-6α-formamidopenicillanate 1α-oxide

diphenylmethyl 7β-acetamido>-7α-formamido-3-<(1-methyl-1H-tetrazol-5-yl)thiomethyl>ceph-3-em-4-carboxylate

benzyl 6β-<(D)-2-(4-ethyl-2,3-dioxopiperazin-1-ylcarbonylamino)-2-(3,4-diacetoxyphenyl)acetamido>-6α-formamidopenicillanate 1α-oxide

Acetic acid 2-acetoxy-5-{(R)-chlorocarbonyl-[(4-ethyl-2,3-dioxo-piperazine-1-carbonyl)-amino]-methyl}-phenyl ester