SMILES: C1=CC2=C(C=C1O)C(=CN2)C[C@@H](C(=O)[O-])[NH3+]
Description: The molecule is an amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of 5-hydroxy-L-tryptophan; major species at pH 7.3. It is a tautomer of a 5-hydroxy-L-tryptophan.