Human Endogenous Metabolite
H-Phe-Phe-OH (Phe-Phe) is a peptide made of two phenylalanine molecules. Phenylalanine is an essential amino acid and the precursor for the amino acid tyrosine. It is the precursor of catecholamines in the body. The psychotropic drugs (mescaline, morphine, codeine, and papaverine) also have phenylalanine as a constituent. The H-Phe-Phe-OH recognition motif of the Alzheimer's Abeta peptide is the smallest peptide able to assemble into higher -order structures.