A series of vallesamine-type alkaloids was isolated from Alstonia angustiloba and Alstonia pneumtophora. Besides the known alkaloids vallesamine 111 and O-acetylvallesamine [2], the following new alkaloids were found: angustilobine A 131, 15-hydroxy-angustilobine A [SI, angustilobine B 141, 4,6-secoangustilobinal 161, 6,7-seco-19,20-epoxyangustilobine B [T, 6,7-seco-6-cyanostemmadenine [8],6,7-sec~angustilobine B 191, and nor-6,7 secoangustilobine A [lo]. The structures are based on the spectral data of these alkaloids. In the course of a study of alkaloids in various parts ofAIstonia angustiloba Miq. and Alstonia pneumatophora Backer ex L.G. Den Berger (Apocynaceae), a series of vallesamine-type alkaloids was isolated. Besides the known alkaloids vallesamine 117 and acetylvallesamine [2], a series of compounds was found that showed similar spectral properties pointing to a structural relationship. Here we discuss the structures of these alkaloids as they ave been deduced from the 400 MHz 'H-nmr spectra.