Dominique Harakat

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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)
Stilbenes have received much attention during the last two decades following the discovery of resveratrol in wine. Since then, there have been a growing number of papers reporting various biological activities of naturally occurring stilbenes. The aim of this study was to determine new minor stilbenes from Vitis vinifera stalks. Purification of these(More)
Seven acylated flavonol glycosides named elaeagnosides A-G, in addition to seven known flavonoids were isolated from the flowers of Elaeagnus angustifolia. Their structures were elucidated by different spectroscopic methods including 1D, 2D NMR experiments and HR-ESI-MS analysis. In order to identify natural antioxidant and tyrosinase inhibitor agents, the(More)
Five labdane diterpenoids, (3-5), zambesiacolactone A (7) and zambesiacolactone B (8), were isolated from the seeds of Aframomum zambesiacum (Baker) K. Schum., along with five known labdanes and a linear sesquiterpene, nerolidol. Their structures were elucidated by spectroscopic analysis. Their antiplasmodial activity was evaluated in vitro against(More)
During tumor invasion, tumor cells degrade the extracellular matrix. Basement membrane degradation is responsible for the production of peptides with anti-tumor properties. Type XIX collagen is associated with basement membranes in vascular, neuronal, mesenchymal and epithelial tissues. Previously, we demonstrated that the non-collagenous NC1, C-terminal,(More)
A new monodesmosidic spirostanol saponin, along with three known saponins was isolated from Agave macroacantha Zucc leaves. The structure of the new saponin was established as hecogenin-3-O-alpha-L-rhamnopyranosyl (1-->4) beta-D-xylopyranosyl (1-->3)[beta-D-glucopyranosyl (1-->2)] beta-D-glucopyranosyl (1-->4) beta-D-galactopyranoside. The (1)H and (13)C(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)
[structure: see text] A novel seco-dibenzopyrrocoline alkaloid, named oubatchensine 6, and five phenanthroindolizidines (1-5) were isolated from Cryptocarya oubatchensis, and their structures were elucidated. Displacement centrifugal partition chromatography was used to purify compounds 1 and 6. Structure determination of the latter was carried out by mass(More)
From the MeOH extract of leaves of Oxyanthus pallidus, three cycloartane glycosides, named pallidiosides A-C, were isolated together with two known compounds, oleanolic acid and 3-O-β-D-glucopyranosyl-β-sitosterol. The structures of pallidiosides A-C were assigned on the basis of spectral studies and comparison with published literature data. The known(More)