(R)-S-(2-Amino-2-carboxyethyl)-L-homocysteine 535-35-3 56-88-2 Butanoic acid, 2-amino-4-((2-amino-2-carboxyethyl)thio)-, (R-(R*,S*))- CYSTATHIONINE Cystathionine, L- EINECS 200-295-8 L-(+)-Cystathionine L-Cystathionine L-Homocysteine, S-((2R)-2-amino-2-carboxyethyl)- L-Homocysteine, S-(2-amino-2-carboxyethyl)-, (R)-