The structure of isostrychnopentamine, a bisindole monoterpene alkaloid from Strychnos usambarensis

in Phytochemistry (1987), 26(2), 557-560

The alkaloid isostrychnopentamine has been shown to be epimeric with strychnopentamine at the asymmetric carbon atom of the N-methylpyrrolidin-2-yl group. Its IUPAC name is also given.

12'-Hydroxystrychnobiline, nouvel alcaloïde bisindolinique du Strychnos variabilis

in Journal of Natural Products (1983), 46(5), 638-645

12'-hydroxystrychnobiline, a new unsymmetrical bisindole alkaloid, was isolated from the root barks of Strychnos variabilis. Its structure was established by acid hydrolysis and by spectral analysis ... [more ▼]

12'-hydroxystrychnobiline, a new unsymmetrical bisindole alkaloid, was isolated from the root barks of Strychnos variabilis. Its structure was established by acid hydrolysis and by spectral analysis, especially by 1H-nmr at 360MHz. We compare its absolute stereochemistry with that of other alkaloids that contain an oxazine ring. [less ▲]

Deux nouveaux alcaloïdes quaternaires isolés à partir des feuilles du Strychnos usambarensis GILG du Rwanda: Nb-méthyl hydroxy-10 et hydroxy-11 usambarines

in Journal de Pharmacie de Belgique (1983), 38(4), 211-218

Two new isomeric bis-indole alkaloids have been isolated from Strychnos usambarensis leaves. They are phenolic dimers of the "usambarine (usambarane) type" and correspond to the Nb-methyl-derivatives of ... [more ▼]

Two new isomeric bis-indole alkaloids have been isolated from Strychnos usambarensis leaves. They are phenolic dimers of the "usambarine (usambarane) type" and correspond to the Nb-methyl-derivatives of 10- and 11-hydroxy-usambarine. The structure elucidation and the stereochemistry of these molecules are discussed from their spectroscopic properties (UV,IR,MS, CD , NMR). TLC comparison with quaternarized 10- and 11-hydroxy-usambarine provides a corroborative structural proof. The separation of the two alkaloids by "DCCC" (Droplet Counter current Chromatography) gives a new example of the application of this suitable technique for the separation of polar coumpounds that it is always very difficult to purify and separate. [less ▲]

New indole aldehydic alkaloids of Strychnos variabilis

in Tetrahedron Letters (1980), 21

Two isomeric pairs of novel indoline aldehydic alkaloids have been isolated from the root barks of Strychnos variabillis. The isomerism finds its origin in the facile isomerisation of C16 and is set up ... [more ▼]

Two isomeric pairs of novel indoline aldehydic alkaloids have been isolated from the root barks of Strychnos variabillis. The isomerism finds its origin in the facile isomerisation of C16 and is set up rapidly at room temperature. So, they could be the biogenetic starting point of two series of alkaloids which have a different stereochemistry for C16: the "retuline" series and the epimer "isoretuline" series. [less ▲]