Browsing by Autor "Jean-Charles Gantier"

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Antiprotozoal activity of dehydrozaluzanin C, a sesquiterpene lactone isolated from Munnozia maronii (asteraceae)
(Wiley, 1993) Alain Fournet; Victoria Muñoz; François Roblot; Reynald Hocquemiller; André Cavé; Jean-Charles Gantier
Abstract The petroleum ether extract of the leaves of Munnozia maronii was found to inhibit in vitro the growth of promastigote forms of Leishmania and epimastigote forms of Trypanosoma cruzi with an IC 90 of 25 μg/mL. Activity‐guided fractionation of the extract by chromatography identified the sesquiterpene lactone 1 of the guaiane series. The complete structure of 1 was elucidated using 1 H and 13 C NMR experiments at high field. The isolated compound was shown to be a new natural guaianolid, dehydrozaluzanin C, previously known as synthetic oxidative derivative of zaluzanin C (Romo de Vivar et al. , 1967). This compound inhibited, in vitro , the growth of 12 strains of Leishmania and 15 strains of T. cruzi at concentrations between 50 and 2.5 μg/mL. The leishmanicidal activity of dehydrozaluzanin C was tested on BALB/ c mice infected with amastigote forms of Leishmania amazonensis . Dehydrozaluzanin C reduced the severity of L. amazonesis lesions in BALB/ c mice but was less active than the reference compound Glucantime.
In Vitro and In Vivo leishmanicidal activities of natural and synthetic quinoids
(Wiley, 1993) Michel Sauvain; Jean‐Pierre Dedet; Nicole Kunesch; J Poisson; Jean-Charles Gantier; Philippe Gayral; Gerhard Kunesch
Abstract The activities of various compounds isolated from plants traditionally used against leishmaniasis in populations from the tablelands of the Guyanas have been examined. The leishmanicidal activity of plant extracts was evaluated by in vitro testing on promastigote and amastigote stages of Leishmania amazonensis and by in vivo tests on L. amazonensis in mice. The leaves of Jacaranda copaia (Aublet) D. Don yielded two compounds: ursolic acid and jaracanone. Ursolic acid showed an interesting activity in vitro with an ED 50 against amastigotes of 0.02 mM and no toxicity to macrophages at twice this dose. Jacaranone displayed a marked activity against promastigotes in vitro with an ED 50 of 0.02 mM. Both compounds have weak in vivo antileishmanial activity. Similar synthetic compounds such as quinol and quinone acetates were prepared and showed increased activity in experimental cutaneous leishmaniasis in mice.
Isolation of leishmanicidal triterpenes and lignans from the Amazonian lianaDoliocarpus dentatus (dilleniaceae)
(Wiley, 1996) Michel Sauvain; Nicole Kunesch; J Poisson; Jean-Charles Gantier; Philippe Gayral; Jean-Pierre Dedet
The in vitro antileishmanial activity of triterpenes and lignans of an Amazonian medicinal plant, Doliocarpus dentatus (Aublet) Standley, is reported for the first time against amastigotes of Leishmania amazonensis. Terpenes, for example, betulinic acid, betulin and betulinaldehyde were isolated by bioassay-linked extraction. The lignans were characterized as (+) pinoresinol, (+) medioresinol and (−) lirioresinol B.