The molecule is a peptide anion obtained by deprotonation of the the three carboxy groups and protonation of the amino group of S-(2-carboxy-2-methylbut-3-en-2-yl)-glutathione; major species at pH 7.3. It is a conjugate base of a S-(2-carboxy-2-methylbut-3-en-2-yl)glutathione.
(2S)-2-azaniumyl-5-[[(2R)-3-(2-carboxylatobut-3-en-2-ylsulfanyl)-1-(carboxylatomethylamino)-1-oxopropan-2-yl]amino]-5-oxopentanoate