Dioxindolyl-L-alanine;Dioxindolyl-L-alanine (Mixture of DiastereoMers);Tryptophan EP Impurity B (Mixture of Diastereomers);Tryptophan Impurity 2(Tryptophan EP Impurity B);1H-Indole-3-propanoic acid, α-amino-2,3-dihydro-3-hydroxy-2-oxo-, (αS)-;(S)-2-amino-3-[(3RS)-3-hydroxy-2-oxo-2,3-dihydro-1H-indol-3-yl]propanoic acid;N-Acetyltryptophan EP Impurity B;Dioxyindolylalanine