The structure of regalamine
SummaryOn the basis of UV, IR, NMR, and mass spectra and chemical transformations the structure of 11,12-dihydroxy-2-methoxy-1,12-epoxyhexahydrohomoproaporphine has been proposed for regalamine.
Alkaloide Von Bulbocodium vernum L Inhaltstoffe der Liliaceae‐Wurmbaeoideae. 75. Mitteilung
From whole plants of Bulbocodium vernum L. the flavone luteoline (I) and the alkaloids colchicine (II), N-formyl-N-deacetylcolchicine (III), 3-demethylcolchicine (V), (+)-bulbocodine (IX) and (−)-kreysigine (XI) were isolated in crystals. The presence of 2-demethylcolchicine (IV), s- (VII) and γ-lumicolchicine (VIII), demecolcine (VI) and five not identified alkaloids was demonstrated by thin-layer chromatography. On the basis of ultraviolet, infrared and mass spectra, PMR.-analysis (Overhauser effect), and circular dichroism, the (6a-R, 8a-S)homo-proaporphine structure IX, with one methoxy group at C-2, has been assigned to (+)-bulbocodine. The (6a-R)-structure (XI) was deduced for (−)-kreysigine by comparing its optical rotation and circular dichroism which the values of (−)-multifloramine (X), the structure of which is known.
Nuclear overhauser effect studies on fumaria alkaloids
The nuclear Overhauser effect has been used to confirm the structures proposed for two alkaloids isolated from Fumaria officinalis L.