(D)-Ethionine 4-04-00-03194 (Beilstein Handbook Reference) 535-32-0 BRN 1722527 Butyric acid, 2-amino-4-(ethylthio)-, D- D-Ethionine D-Homocysteine, S-ethyl- D-Homocysteine, S-ethyl- (9CI) EINECS 208-612-1 HSDB 3570 NSC 97927 d-2-Amino-4-(ethylthio)butyric acid