(+-)-Norvaline 2-Aminovaleric acid 760-78-1 AI3-18299 DL-2-Aminopentanoic acid DL-NORVALINE DL-alpha-Aminovaleric acid EINECS 212-082-7 NSC 7904 Norvaline Valeric acid, 2-amino-, DL- alpha-DL-Aminopentanoic acid