Hygrine, an intermediate in biosynthesis of tropane alkaloids, was formed non-enzymatically by the coupling of γ-methylaminobutyraldehyde with either acetoacetic acid or acetonedicarboxylic acid. When these ketoacids were fed to a tropane alkaloid-free culture of tobacco roots, hygrine formation was observed. A possible process of this reaction is discussed. © 1988.
Endo, T., Hamaguchi, N., Hashimoto, T., & Yamada, Y. (1988). Non-enzymatic synthesis of hygrine from acetoacetic acid and from acetonedicarboxylic acid. FEBS Letters, 234(1), 86–90. https://doi.org/10.1016/0014-5793(88)81309-7