ALKALOIDS OF ALSTONIA ANGUSTIFOLIA

Article abstract of DOI:10.1016/0031-9422(88)83053-X

Thirty-one alkaloids have been isolated from the leaves and from the stem bark of Alstonia angustifolia from Malaysia.Twenty of them were known compounds: yohimbine, O-acetyl yohimbine, pleiocarpamine, fluorocarpamine, cathafoline, cabucraline, N-1 desmethylquaternine, vincamajine, normacuisine B, lochnerine, affisine, akuammicine, 11-methoxyakuammicine, antrihine, alstonisine, alstoneine, alstophylline, macralstonine, villalstonine and tetrahydrocantleyine.Among the novel 11 alkaloids, three were monomers: 19,20-dehydro-10-methoxytalcarpime, 19,20-dehydro-O-acetyl yohimbine and hydroxystrictamine, and eight were dimers: villalstonine N-4'-oxide, 10-methoxy villalstonine, 10-methoxyvillalstonine N-4'-oxide, 10-methoxymacrocarpamine, 10-methoxymacrocarpamine N-4'-oxide, angusticraline, alstocraline an d foliacraline.Structural elucidation of the new alkaloids was based on spectral data analysis including high field 1H and 13C NMR.