5-Thia-1-azabicyclo(4.2.0)oct-2-ene-2-carboxylic acid, 7-((5-amino-5-carboxy-1-oxopentyl)amino)-3-(hydroxymethyl)-7-methoxy-8-oxo-, (6R-(6alpha,7alpha,7(R*)))- 58301-37-4 SF 1623B SF-1623B