1962-83-0 2-Amino-5-formylvaleric acid 2-Aminoadipate semialdehyde 34897-38-6 6-Oxo-DL-norleucine Allysine Norleucine, 6-oxo- Norvaline, 5-formyl- alpha-Aminoadipic acid delta-semialdehyde alpha-Aminoadipic delta-semialdehyde alpha-Aminoadipic semialdehyde