3-Pyridineacetic acid, 5-amino-2-carboxy-1,4,5,6-tetrahydro-4-oxo-, (-)- 5-Amino-2-carboxy-4-oxo-1,4,5,6-tetrahydropyridine-3-acetic acid 78416-84-9 Gostatin Gostatine NSC 382261