5 结果
Quadrigemine B, quadrigemine A, isopsychotridine C and psychotridine, isolated from PSYCHOTRIA FORSTERIANA, are potent inhibitors of the aggregation of washed human platelets induced by ADP, collagen or thrombin. The four compounds are active in the 1-10 microM range. The quadrigemine-type alkaloids
Fractionation of an alkaloid extract of Psychotria colorata flowers led to the isolation of six alkaloids, identified by UV, 1D and 2D NMR, and MS as (-)-calycanthine, isocalycanthine, (+)-chimonanthine, hodgkinsine, quadrigemine C, and a new alkaloid (1), whose structure was deduced by X-ray
The effects of psycholeine, a plant alkaloid, were investigated on binding of radiolabelled somatostatin ([125I]N-Tyr-SRIF) and on somatostatin (SRIF)-induced inhibition of adenylate cyclase activity and growth hormone (GH) secretion by rat anterior pituitary cells. Psycholeine was shown to displace
Bioactivity-guided purification of a crude alkaloid extract of Psychotria oleoides has afforded a new alkaloid, psycholeine [1], together with quadrigemine C [2], a tetrameric pyrrolidinoindoline compound of unknown stereochemistry. A comparison study of nmr and cd spectra of quadrigemine C and
The chemical study of two Rubiaceae from New Caledonia, Psychotria lyciiflora and Psychotria oleoides, led to the isolation of several pyrrolidinoindoline alkaloids. Two dimers, the known meso-chimonanthine (9) and the new Nb-desmethyl-meso-chimonanthine (5), and a known trimer, hodgkinsine (1),