5-Thia-1-azabicyclo(4.2.0)oct-2-ene-2-carboxylic acid, 7-(((3,4-dihydroxyphenyl)(((4-ethyl-2,3-dioxo-1-piperazinyl)carbonyl)amino)acetyl)amino)-7-(formylamino)-8-oxo-3-((1,3,4-thiadiazol-2-ylthio)methyl)-, monosodium salt, (6R-(6alpha,7beta))-