(6R,7S)-7-[[(2R,3S)-2-[(4-ethyl-2,3-dioxopiperazine-1-carbonyl)amino]-3-hydroxybutanoyl]amino]-7-methoxy-3-[(1-methyltetrazol-5-yl)sulfanylmethyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid (6R,7S)-7-[[(2R,3S)-2-[(4-ethyl-2,3-dioxo-piperazine-1-carbonyl)amino]-3-hydroxy-butanoyl]amino]-7-methoxy-3-[(1-methyltetrazol-5-yl)sulfanylmethyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid (6R,7S)-7-[[(2R,3S)-2-[[(4-ethyl-2,3-dioxo-1-piperazinyl)-oxomethyl]amino]-3-hydroxy-1-oxobutyl]amino]-7-methoxy-3-[[(1-methyl-5-tetrazolyl)thio]methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid (6R,7S)-7-[[(2R,3S)-2-[(4-ethyl-2,3-diketo-piperazine-1-carbonyl)amino]-3-hydroxy-butanoyl]amino]-8-keto-7-methoxy-3-[[(1-methyltetrazol-5-yl)thio]methyl]-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid (6R,7S)-7-[[(2R,3S)-2-[(4-ethyl-2,3-dioxo-piperazin-1-yl)carbonylamino]-3-hydroxy-butanoyl]amino]-7-methoxy-3-[(1-methyl-1,2,3,4-tetrazol-5-yl)sulfanylmethyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid D03423 Cefbuperazone (USAN)