Laurence Voutquenne-Nazabadioko

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Hederagenin saponins are largely represented in nature and possess many biological activities such as haemolytic, antiviral, fungicidal, molluscicidal or cytotoxic, partially due to their interaction with the cell membrane. The lysis of erythrocytes (haemolysis) is a simple test to evaluate this adsorption, and this activity has been linked to the structure(More)
The evaluation of the biocidal activity of the fruit of Solanum sisymbriifolium involving non target organisms such as aquatic insects, fish and snails lead to the isolation of the steroidal alkaloids, solamargine and β-solamarine, from the active fractions. The fractions A3 and C, with biological activity against fish, snail and aquatic insect and larvae,(More)
Five triterpenoid saponins, caryocarosides II-22 (3), III-22 (4), II-23 (5), III-23 (6), and II-24 (7), have been isolated from the methanol extract of the stem bark of Caryocar villosum, along with two known saponins (1-2). The seven saponins are glucuronides of hederagenin (II) or bayogenin (III). Caryocaroside II-24 (7) is an unusual galloyl ester(More)
Two dihydroisocoumarin glucosides have been isolated from the stem bark of Caryocar glabrum (Aubl.) Pers. Their structures and absolute stereochemistry were established on the basis of extensive 1D and 2D NMR, UV, IR, HRESIMS, and CD studies. These compounds represent the first members of a new biogenetic pathway for the isocoumarins nucleus involving(More)
Glycosylation of hederagenin with the trichloroacetimidate derivatives of six commercial disaccharides (D-cellobiose, D-lactose, D-maltose, D-melibiose, D-gentiobiose, D-isomaltose) was performed giving the protected saponins in high yields. Deprotection then gave the saponins which were transformed into the corresponding methyl esters. The hemolytic(More)
Three new bidesmosidic saponins (1-3) and a new ursane triterpenoid, 2α,3β,11α,23-tetrahydroxyurs-12-en-28-oic acid (4), along with seven known compounds, were isolated from a methanolic extract of the leaves of Symplocos lancifolia. The bidesmosidic saponins were found to possess the same sugar unit part, composed of two β-d-glucose moieties and one(More)
Through a bioassay-guided phytochemical investigation involving mushroom tyrosinase inhibitory activity, seven farnesyl diglycosides ( 1 - 7), five flavonoids ( 8 - 12), one trimeric proanthocyanidin ( 13), two triterpenes ( 14 and 15), and one cerebroside ( 16), were isolated from the leaves of Caledonian Guioa villosa. Among them, crenulatosides E, F and(More)
BACKGROUND Naturally occurring flavonoids have been reported to possess various pharmacological properties. The aim of this study was to evaluate the antimicrobial and antioxidant activities of the MeOH extract and flavonoids from the leaves of Oncoba spinosa, a plant used for the treatment of syphilis, wounds and sexual impotence. METHODS The plant(More)
Mushroom tyrosinase inhibitory activity of methanol extracts and polar fractions of the stem bark of Caryocar villosum and C. glabrum has been assessed. Seven new phenolic glycosides (1-7) were isolated from the most active fractions, along with 15 known compounds (8-22). The structures of these compounds were established on the basis of spectroscopic(More)
INTRODUCTION Alphitonia neocaledonica (Rhamnaceae) is an endemic tree of New Caledonia. Although three flavonoids have been identified in the leaves, the secondary metabolite profile of the fruits has never been investigated. OBJECTIVE Phytochemical investigation of A. neocaledonica fruits and evaluation of their anti-oxidant, anti-tyrosinase and(More)