68335-21-7 Benzenebutanoic acid, alpha-amino-2-((2-((3-amino-1-oxopropyl)amino)-1-(3,4-dihydroxyphenyl)ethyl)amino)-gamma-oxo-, stereoisomer N(ar)-(alpha-(3-Aminopropionylaminomethyl)-3,4-dihydroxybenzyl)-L-kynurenine Papiliochrome II