Tags: Chemical Compound, Chemical Substance.
Tryptophan (IUPAC-IUBMB abbreviation: Trp or W; IUPAC abbreviation: L-Trp or D-Trp; sold for medical use as Tryptan) is one of the 22 standard amino acids and an essential amino acid in the human diet as demonstrated by its growth effects on rats. It is encoded in the standard genetic code as the codon UGG.