β-Carboline alkaloids from Psychotria barbiflora DC. (Rubiaceae)

Absence of alkaloids in Psychotria carthagenensis Jacq. (Rubiaceae).

Psychotria viridis and P. carthagenensis are often discussed in relation to the hallucinogenic beverage Ayahuasca, used for religious, medicinal and social purposes. The significance of including Psychotria species in this beverage has been understood on the basis of substantial amounts of tryptamine alkaloids detected on leaves of both P. viridis and P. carthagenensis. Nevertheless, there is a...

Cytotoxic activity of polyindoline alkaloids of Psychotria forsteriana (Rubiaceae) (1).

Three novel β-carboline alkaloids from Gelsemium elegans.

Three novel β-carboline alkaloids characterized with a unique degraded monoterpenoid moiety, gelebolines A-C (1-3), together with 11 known alkaloids of different types, were isolated from the roots of Gelsemium elegans. The structures of new alkaloids were established on the basis of analysis of spectroscopic data. It is the first example for report of β-carboline from genus Gelsemium (Loganiac...

13C-NMR Spectral Data of Alkaloids Isolated from Psychotria Species (Rubiaceae).

The genus Psychotria (Rubiaceae) comprises more than 2000 species, mainly found in tropical and subtropical forests. Several studies have been conducted concerning their chemical compositions, showing that this genus is a potential source of alkaloids. At least 70 indole alkaloids have been identified from this genus so far. This review aimed to compile 13C-NMR data of alkaloids isolated from t...

/?-Carboline Alkaloids from Ribes nigrum L

From Ribes nigrum L. two ß-carboline alkaloids (deshydroxymethyl flazin (1) and flazin methyl ether (2)) could be isolated in minute amounts. The structure elucidation is described. The two compounds are present in the freshly pressed juice, but they are also formed during storage of the juice by condensation of tryptophane with ascorbic acid or its degradation products. This could be shown by ...