Ten new indole alkaloids (1-10) comprising five ibogan, two aspidosperman, one vincamine, and two bisindole alkaloids, in addition to 32 known alkaloids, were isolated from the stem-bark extract of a Malayan Tabernaemontana corymbosa. The structures of these alkaloids were determined based on analysis of the NMR and MS data and, in five instances (1, 3, 5, 6, 8), confirmed by X-ray diffraction...
Abstract Conomicidines A and B (1a and 2a, resp.) together with the diastereomeric isoconomicidines A and B (1b and 2b, resp.) were isolated from Tabernaemontana corymbosa as unresolvable mixtures of the (1′S,2′S)‐ and (1′R,2′R)‐diastereoisomers (i.e., 1a and 1b; 2a and 2b). These novel natural products are constituted from the union of an iboga alkaloid, ibogaine, and hydroxycinnamyl alcohol...