The molecule is a sulfonium betaine obtained by deprotonation of the carboxy groups and protonation of the amino group of S-adenosyl-S-carboxymethyl-L-homocysteine. Major microspecies at pH 7.3 It is a L-alpha-amino acid zwitterion and a sulfonium betaine. It is a conjugate base of a S-adenosyl-S-carboxymethyl-L-homocysteine.
(2S)-4-[[(2S,3S,4R,5R)-5-(6-aminopurin-9-yl)-3,4-dihydroxyoxolan-2-yl]methyl-(carboxylatomethyl)sulfonio]-2-azaniumylbutanoate