115369-52-3 ME 1228 ME1228 Pyridinium, 4-(((7-(((2-amino-4-thiazolyl)((1-carboxyethoxy)imino)acetyl)amino)-2-carboxy-8-oxo-5-thia-1-azabicyclo(4.2.0)oct-2-en-3-yl)methyl)thio)-1-ethyl-, hydroxide, inner salt, (6R-(6-alpha,7-beta(Z(S*))))-