5-Oxo-L-proline, compound with 5-hydroxy-6-methylpyridine-3,4-dimethanol (1:1) 74536-44-0 EINECS 277-913-8 L-Proline, 5-oxo-, compd. with 5-hydroxy-6-methylpyridine-3,4-dimethanol (1:1) Metadoxine