Browsing by Autor "Alexis Valentin"

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Activity of acnistins against Leishmania mexicana, Trypanosoma cruzi and Plasmodium falciparum
(2009) Bernardo Chataing; Antoine Hocquette; S.B. Díaz; Alexis Valentin; Alfredo Usubillaga
Acnistin A and E, two withanolides with a bicyclic side-chain at C-17, isolated from the leaves of Acnitus arborescens (L) Schlecht that grows in the Venezuelan Andes inhibited the growth of Leishmania mexicana and Trypanosoma cruzi in cultured medium. On the other hand acnistins A, E, and L, also inhibited the growth of a chloroquine-resistant strain and a chloroquine-sensitive strain of Plasmodium falciparum in cultured medium. Data indicated that acnistins exerted a higher inhibitory activity upon these parasites that ketoconazole, mevastatin and lapachol in the same conditions of assay.
Anti-Leishmanial Lindenane Sesquiterpenes from<i>Hedyosmum angustifolium</i>
(Thieme Medical Publishers (Germany), 2009) Lucia Acebey; Valérie Jullian; Denis Séréno; Séverine Chevalley; Yannick Estevez; Claude Moulis; Stephan Beck; Alexis Valentin; Alberto Giménez; Michel Sauvain
The aim of this work is the isolation of anti-leishmanial compounds from the ethyl acetate extracts of the bark of HEDYOSMUM ANGUSTIFOLIUM. We have successfully isolated and characterized five sesquiterpenes: one new compound (oxyonoseriolide, 1), one compound isolated for the first time from a natural source (hedyosmone, 2), and three known sesquiterpenes (onoseriolide, 3; chloranthalactone A, 4; and spathulenol, 5) that had not been previously isolated from H. ANGUSTIFOLIUM. The biological activities of 1- 5 showed that onoseriolide ( 3) was the most active compound against axenic amastigotes from LEISHMANIA AMAZONENSIS and L. INFANTUM. Moreover, it was still active on the intramacrophagic amastigotes of L. INFANTUM. The isolated compounds have also been tested on PLASMODIUM FALCIPARUM and against various mammalian cell lines.
Antimalarial Activity and Cytotoxicity of (-)-Roemrefidine Isolated from the Stem Bark of<i>Sparattanthelium amazonum</i>
(Thieme Medical Publishers (Germany), 1999) Verónica Francisca Loewe Muñoz; Michel Sauvain; Patricia Mollinedo; Jorgia Callapa; I. Gina Rojas; A. Giménez; Alexis Valentin; M. Mallié
(-)-Roemrefidine, an aporphine alkaloid isolated from Sparattanthelium amazonum Martius (Hernandiaceae) a vine from Bolivia, has been found to be active against both resistant and sensitive strains of Plasmodium falciparum in vitro and against P. berghei in mice. The compound demonstrated no cytotoxic activity against three cell lines (KB, HEp-2 and HeLa).
Antiplasmodial activity of Aspidosperma indole alkaloids
(Elsevier BV, 2002) Anne‐Claire Mitaine‐Offer; Michel Sauvain; Alexis Valentin; Jorgia Callapa; M. Mallié; Monique Zèches-Hanrot