80730-81-0 L 642946 L-642946 Pyridinium, 4-((2-carboxy-3-(((5-((carboxymethyl)thio)-1,3,4-thiadiazol-2-yl)thio)methyl)-8-oxo-5-thia-1-azabicyclo(4.2.0)oct-2-en-7-yl)amino)-1-(phenylmethyl)-, hydroxide, inner salt, monosodium salt, (6R-trans)-