13073-35-3 2-Amino-4-(ethylthio)butyric acid Butanoic acid, 2-amino-4-(ethylthio)-, (S)- Butyric acid, 2-amino-4-(ethylthio)- Butyric acid, 2-amino-4-(ethylthio)-, L- Ethionine Homocysteine, S-ethyl- L-Ethionine L-Homocysteine, S-ethyl- NSC82393 WLN: QVYZ2S2