Strychnohexamine from Strychnos icaja; the first naturally occurring indolomonoterpenoid trimeric alkaloid

Peer reviewe

Chrysopentamine, an antiplasmodial anhydronium base from Strychnos usambarensis leaves

A new derivative of strychnopentamine was isolated from the leaves of Strychnos usambarensis. This compound, named chrysopentamine, was identified by detailed spectroscopic methods (UV, IR, HR-ESI-MS, 1D and 2D NMR). Chrysopentamine presented an original hydroxy substitution on C-14 and an aromatization of the ring D of strychnopentamine leading to anhydronium base proper-ties and exhibited strong antiplasmodial properties (IC50 less than 1 muM)

Isolation of indole alkaloids from Catharanthus roseus by centrifugal partition chromatography in the pH-zone refining mode

International audienceCentrifugal partition chromatography (CPC) in the pH-zone refining mode allowed a preparative and efficient isolation of vindoline, vindolinine, catharanthine and vincaleukoblastine from a crude mixture of Catharanthus roseus alkaloids. The separation protocol was tested with a synthetic mixture of vindoline, catharanthine and vincaleukoblastine. The fraction content was analyzed and the results compared with theoretical chromatograms obtained by numerical simulation. The increase in injected sample mass results in an improvement of the purity of the isolated compounds. This observation, confirmed by theory, is of prime importance for the development of preparative pH-zone refining CPC as a preparative separation method

Five labdane diterpenoids from the seeds of Aframomum zambesiacum

Five labdane diterpenoids, (3-5), zambesiacolactone A (7) and zambesiacolactone B (8), were isolated from the seeds of Aframomum zambesiacum (Baker) K. Schum., along with five known labdanes and a linear sesquiterpene, nerolidol. Their structures were elucidated by spectroscopic analysis. Their antiplasmodial activity was evaluated in vitro against Plasmodium falciparum. Compound 3 was the most active with an IC50 value of 4.97 mu M. (c) 2005 Elsevier Ltd. All rights reserved

Moandaensine, a dimeric indole alkaloid from Strychnos moandaensis (Loganiaceae)

Moandaensine contains a rare anhydronium base subunit. It presents a moderate antiplasmodial activity with IC values of 11.2 microM and 9.2 microM against , respectively, the chloroquino sensitive FCA 20 GHA and chloroquino resistant W2 strains of Plasmodium falciparu