N-(carboxymethyl)-N-[2-(2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl)

N-(Carboxymethyl)-N-[2-(2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl)ethyl]-mono(4-methylbenzenesulfona-te)glycine