D-Phenylalanine tert-butyl ester is a protected form of D-Phenylalanine (P319410). D-Phenylalanine is an essential amino acid that serves as a primary precursor for the biosynthesis of catecholamines in the body. D-Phenylalanine is also known to antagonize stress-induced analgesia in humans, and also acts as an anti-enkephalinase agent.