α-(4-Ethyl-2,3-dioxo-1-piperazinecarboxamido)benzylpenilloic Acid

[2R-[2α(R),4β]]-2-[[[[[(4-Ethyl-2,3-dioxo-1-piperazinyl)carbonyl]amino]phenylacetyl]amino]methyl]-5,5-dimethyl-4-thiazolidinecarboxylic Acid