deacetylcephalosporin C Antibiotic WS-3442E Desacetylcephalosporin C WS-3442E (6R,7R)-7-(5-amino-5-carboxypentanamido)-3-(hydroxymethyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid Cefmenoxime Impurity 37 Desacetyl Cephalosporin C Disodium Salt 5-Thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, 7-[[(5R)-5-amino-5-carboxy-1-oxopentyl]amino]-3-(hydroxymethyl)-8-oxo-, (6R,7R)-