[Alkaloids from Annonaceae XLVII*: Alkaloides of Guatteria ouregou**].

The Guianese Annonaceous plant GUATTERIA OUREGOU D UN. has yielded fourteen isoquinoline alkaloids, five of which are novel. They belong to several structural types; attention is specially drawn to three original skeletons, namely 7-hydoxy-7-methyl aporphinoids, 7- GEM-dimethyl aporphinoids and alpha- GEM-dimethyl cularinoids. The results concerning solvent shift in (1)H NMR spectra of some of these alkaloids are emphasized. Finally the phytochemical significance of the isolated alkaloids is discussed considering their chemotaxonomic and biogenetic interest.