Browsing by Autor "Georges Massiot"

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4-Quinolinone alkaloids from Dictyoloma peruviana
(Elsevier BV, 1995) Catherine Lavaud; Georges Massiot; Carmen Vásquez; Christian Moretti; Michel Sauvain; Luisa Balderrama
A Novel Antiprotozoal Aminosteroid from Saracha punctata
(American Chemical Society, 1998) Christian Moretti; Michel Sauvain; Catherine Lavaud; Georges Massiot; José A. Bravo; Verónica Francisca Loewe Muñoz
A new aminosteroid, 3beta-amino-22,26-epiminocholest-5-ene named sarachine (1), and two known flavonoids, eriodictyol (2) and 7-O-beta-D-glucopyranosyl-eriodictyol (3), were isolated from the leaves of Saracha punctata. The alkaloid was found to inhibit the growth of Leishmania braziliensis promastigotes (100% at 25 microM) and of Trypanosoma cruzi epimastigotes in culture (50% at 25 microM) and showed a strong in vitro antiplasmodial activity with an IC50 of 25 nM.
Activité antipaludique du n-hentriacontanol isolé deCuatresiasp (Solanaceae)
(EDP Sciences, 1992) Eric Deharo; Michel Sauvain; Costanzo Moretti; Bernard Richard; E. Ruiz; Georges Massiot
L’activité antipaludique de l’alcool gras n-hentriacontanol isolé d’une Solanacée bolivienne Cuatresia sp. est appréciée in vivo, par le test classique du traitement de 4 jours, sur Plasmodium berghei et P. vinckei chez la souris. Le produit réduit nettement la virulence de l’infection à P. vinckei. Le n-hentriacontanol appartient à une nouvelle classe de composés naturels antimalariques exploitables en thérapeutique.
Bioactive phenolic glycosides from Amburana cearensis
(Elsevier BV, 1999) José A. Bravo B.; Michel Sauvain; Alberto Gimenez T.; Victoria Muñoz O; Jorgia Callapa; Louisette Le Men‐Olivier; Georges Massiot; Catherine Lavaud
Isolation of Bis-Indole Alkaloids with Antileishmanial and Antibacterial Activities fromPerschiera van heurkii(Syn.Tabernaemontana van heurkii)
(Thieme Medical Publishers (Germany), 1994) Verónica Francisca Loewe Muñoz; C. Moretti; Michel Sauvain; C. Caron; Andrea Porzel; Georges Massiot; Bernard Richard; Louisette Le Men‐Olivier
Extracts from leaves and stem bark of Peschiera van heurkii (Muell. Arg.) L. Allorge (syn. Tabernaemontana van heurkii Muell. Arg., Apocynaceae) have been assayed for antileishmanial and antibacterial activities. The activities were concentrated in the alkaloid fractions which yielded 20 indole and bisindole alkaloids. The strongest leishmanicidal and antibacterial activities were observed with the dimeric alkaloids conodurine (1), N-demethylconodurine (= gabunine) (2), and conoduramine (3). Weak toxicity towards macrophage host cells and strong activity against the intracellular amastigote form of Leishmania were observed for compounds 1 and 2. In vivo, 1 was less active than glucantime (= N-methylglucamine antimonate), the drug of reference, while 2 was devoid of activity at 100 mg/kg.
Triterpene saponins fromMyrsine pellucida
(Elsevier BV, 1994) Catherine Lavaud; Georges Massiot; Jose ́Bravo Barrera; Christian Moretti; Louisette Le Men‐Olivier
Trypanocidal Withanolides and Withanolide Glycosides from Dunalia brachyacantha
(American Chemical Society, 2001) José A. Bravo B.; Michel Sauvain; Alberto Gimenez T.; Elfride Balanza; Laurent Sérani; Olivier Laprévôte; Georges Massiot; Catherine Lavaud
Two new withanolide glycosides, (20R,22R)-O-(3)-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl-1 alpha,12 beta-diacetoxy-20-hydroxywitha-5,24-dienolide (3) and (20R,22R)-O-(3)-beta-D-xylopyranosyl(1-->3)-[beta-D-xylopyranosyl(1-->4)]-beta-D-glucopyranosyl-1 alpha-acetoxy-12 beta,20-dihydroxywitha-5,24-dienolide (4), were isolated from the leaves and root of Dunalia brachyacantha. Their aglycones, (20R,22R)-1 alpha,12 beta-diacetoxy-3 beta,20-dihydroxywitha-5,24-dienolide (or 1 alpha,12 beta-diacetyldunawithagenine) and (20R,22R)-1 alpha-acetoxy-3 beta,12 beta,20-trihydroxywitha-5,24-dienolide (or 1 alpha-acetyl-12 beta-hydroxydunawithagenine), are novel. The known 18-acetoxywithanolide D (1) and 18-acetoxy-5,6-deoxy-5-withenolide D (2) were also isolated from the leaves. These last two compounds were shown to be responsible for the trypanocidal, leishmanicidal, and bactericidal activities manifested by the crude ethanolic extract. The structures were deduced from spectroscopic data and on the basis of chemical evidence.