4-Thia-1-azabicyclo(3.2.0)heptane-2-carboxylic acid, 6-(((((2-(4-((2-(acetylamino)-1-oxopropyl)amino)phenyl)-1,4-dihydro-4-oxo-5-pyrimidinyl)carbonyl)amino)(4-hydroxyphenyl)acetyl)amino)-3,3-dimethyl-7-oxo-, monosodium salt, (2S-(2-alpha,5-alpha,6-beta(S*(R*))))- 79033-91-3