Aspidosperma-Hunteria alkaloids

Both antipodes of several Aspidosperma and Hunteria alkaloids are known to occur, but it is uncommon to find more than one in a single plant. 

When NMR and mass spectrometry became available, a large number of alkaloids from various apocynaceous plants were investigated (e.g. species of the genera Alstonia, Aspidosperma, Conopharyngia, Gabunia, Hunteria, Iboga, Oncinotis, Rauwolfia, Vinca). Villalstonine was the first bisindole alkaloid whose structure was elucidated by mass spectral analysis. 

C19H26N2, Mr 282.43, mp. 147-149 °C soluble in acetone, chloroform, dilute acids. A monoterpenoid indole alkaloid of the Aspidosperma type, Q. occurs in both enantiomeric forms the (+)-form, (aJu +98° (CHCI3), in leaves and root bark of Pleiocarpa species as well as the bark of Stemmadenia species the (-)-form, [aJi, -100° (CHCI3), in Aspidosperma quebra-cho-blanco and other Aspidosperma species as well as Gonioma, Hunteria, and Rhazya species. 

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