Cefoperazone EP Impurity B

Chemical Name: (6R,7R)-7-[[(2R)-2-[[(4-ethyl-2,3-dioxopiperazin-1-yl)carbonyl]amino]-2-(4-hydroxyphenyl)acetyl]amino]-3-[(4-methyl5-thioxo-4,5-dihydro-1H-tetrazol-1-yl)methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid (as per EP)