An Alstonia alkaloid obtained from A. scholaris R. Br., this base also occurs in
Rauwolfia vornitora. It has [α]D - 47° (CHCI3). The ultraviolet spectrum in
neutral solution (EtOH) has absorption maxima at 237 and 287 mil, while in
acidic solution (perchloric acid), there are absorption maxima at 239, 244 and
305 mil. A methoxycarbonyl group, an alkyl group and an ether bridge are present
in the molecule. The picrate is obtained as light yellow crystals with m.p. 172-
4°C (dec.) and the methiodide has m.p. 235-7°C.
Lampstand leaves crushed into particles, take 10kg, with 15 times the amount of 1% sulfuric acid aqueous solution percolation extraction, the extract was filtered through the addition of molecular weight cut-off molecular weight 2000 hollow cellulose ultrafiltration membrane ultrafiltration, through the liquid and then added to the molecular weight cut-off molecular weight 300 hollow cellulose nano-filtration membrane concentration, concentrated solution over the AB-8 macroporous resin column, the appropriate amount of water to elute, collect the lower column liquid and the water elution solution with Ammonia adjusted pH9, placed on the precipitation, centrifugation, the precipitate with 90% methanol dissolution reflux dissolution, add 1% of the solution amount of activated carbon decolorization, decolorization of the liquid filtered out of the activated carbon, add 1/10 volume of petroleum ether, stirring fully refrigerated crystals, crystals and then recrystallized with 70% ethanol solution, drying white crystals, that is, the duckweed leaf alkaloids 15g, the content of the detection of 90.5%.
Preparation:
Britten, Smith.,J. Chern. Soc., 3850 (1963)
Isolation:
Chatterjee et al., Tetrahedron Lett., 3633 (1965)
