The molecule is zwitterionic form of S-(5-deoxy-D-ribos-5-yl)-L-homocysteine arising from transfer of a proton from the carboxy to the amino group; major species at pH 7.3. It is a tautomer of a S-(5-deoxy-D-ribos-5-yl)-L-homocysteine.
(2S)-2-azaniumyl-4-[[(2S,3S,4R)-3,4,5-trihydroxyoxolan-2-yl]methylsulfanyl]butanoate