The molecule is a dipeptide zwitterion resulting from transfer of a proton from the carboxy to the amino group of S-[(E)-N-hydroxy-2-(indol-3-yl)ethanimidoyl]-L-cysteinylglycine; major species at pH 7.3. It is a tautomer of a S-[(E)-N-hydroxy-2-(indol-3-yl)ethanimidoyl]-L-cysteinylglycine.
2-[[(2R)-2-azaniumyl-3-[(E)-N-hydroxy-C-(1H-indol-3-ylmethyl)carbonimidoyl]sulfanylpropanoyl]amino]acetate