51263-08-2 EINECS 257-093-8 Sodium hydrogen (6R-(6alpha,7beta))-3-(acetoxymethyl)-7-((5-amino-5-carboxylato-1-oxopentyl)amino)-8-oxo-5-thia-1-azabicyclo(4.2.0)oct-2-ene-2-carboxylate