Browsing by Autor "Philippe Gayral"

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    <i>In Vitro</i> and <i>In Vivo</i> 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.
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    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.