CAS No:58909-56-1(free base),131257-07-3(sodium salt)||Chemical Formula:C12H13N5O5S2 ||Molecular Weight:371.38600 ||Exact Mass:371.03581||(6R,7R)-7-amino-3-(((2-methyl-5,6-dioxo-1,2,5,6-tetrahydro-1,2,4-triazin-3-yl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid