0000000000014939
AUTHOR
Jean Paul Dzoyem
showing 6 related works from this author
Flavans and other chemical constituents of Crinum biflorum (Amaryllidaceae)
2019
Abstract The ethyl acetate extract from the whole plant of Crinum biflorum Rottb. Showed a moderate activity against Enterococcus faecalis. Its phytochemical investigation led to the isolation of a new flavan-3-ol derivative namely (2R,3R)-3-hydroxy-7-methoxy-3′,4′-methylenedioxyflavan, together with (2S)-7-hydroxy-3′,4′-methylenedioxyflavan, (2R,3R)-7-methoxy-flavan-3-ol, (2S)-7-hydroxy-3′,4′-dimethoxyflavan, 3′,7-dihydroxy-4′-methoxyflavan, 4′,7-dimethoxy-3′-hydroxyflavan, farrerol, β-sitosterol, β-sitosterol-3-O-β-D-glucopyranoside, oleanolic acid, kaempferol, pancratistatin, lupeol, aurantiamide acetate, Narciprimine and 2,3-dihydroxypropyl palmitate. Their structures were elucidated ma…
Chemical constituents from Anthocleista liebrechtsiana De Wild & T. Durand (Loganiaceae)
2018
Abstract A new steroid derivative, (24S)-3β-hydroxy-7β-methoxyergost-5-ene (1), was isolated along with eleven known compounds: 7α-hydroxysterol (2), β-sitosterol (3), oleanolic acid (4), betulinic acid (5), lupeol (6), swertiaperennin (7), decussatin (8), tetracosanoic acid (9) β-sitosterol-3-O-β- d -glucopyranoside (10), (2R,3S)-2,3-dihydro-2-(3,4-dimethoxyphenyl)-3-hydroxymethyl-5-(2-formylvinyl)-7-hydroxybenzofuran (11) and acacetin 6-C-β- d -glucopyranoside (12) from the tree bark and leaves of Anthocleista liebrechtsiana De Wild & T. Durand. Their structures were elucidated on the basis of spectroscopic (1D and 2D NMR) and mass spectrometric data. Compounds 2 and 7–10 have already bee…
A new ursane-type triterpene oxoglucopyranoside from Crossopteryx febrifuga.
2019
Abstract A new saponin, 3-O-β-d-3-oxo-glucopyranosyl-ursa-12,20(30)-diene-27,28-dioic acid (1), was isolated from the methanol extract of stem bark of Crossopteryx febrifuga together with the known 3β-d-glucopyranosyl-ursa-12,20(30)-diene-27,28-dioic acid (2), shanzhiside methyl ester (3), shanzhiside (4), β-sitosterol (5), β-sitosterol-3-O-β-d-glucopyranoside (6), ursa-12,20(30)-diene-27,28-dioic acid (7), hederagenin (8), and oleanolic acid (9). The structures were established by comprehensive interpretation of their spectral data 1D- (1H and 13C), 2D-NMR (1H-1H COSY, HMQC, HMBC), spectroscopic, and electrospray ionisation time-of-flight mass spectrometry analysis. The isolated compounds …
Antimicrobial secondary metabolites from the medicinal plant Crinum glaucum A. Chev. (Amaryllidaceae)
2020
Abstract Medicinal plants are known as sources of potential antibacterial compounds including alkaloids. The aim of the present study was to evaluate the antibacterial activities of the extract, fractions, and some secondary metabolites isolated from the leaves of Crinum glaucum A. Chev. (Amaryllidaceae). The antibacterial activities were performed with the ethanol (EtOH) extract, as well as with ethyl acetate (EtOAc) and n-butanol (n-BuOH) fractions. Repeated column chromatography of the fractions led to the isolation of several compounds and their structures were elucidated mainly by means of extensive spectroscopic analysis [(one-dimensional (1D) and two-dimensional (2D) nuclear magnetic…
Cytotoxicity of Secondary Metabolites from Dracaena viridiflora Engl & Krause and their Semisynthetic Analogues
2017
The MeOH extract of Dracaena viridiflora was found to display significant cytotoxicity against some cancer cell lines. Systematic phytochemical investigation of this extract led to the isolation and structure elucidation of ten secondary metabolites including five spirostane (1-5) and one furostane (6) steroidal saponins. Furthermore, some acetylated spirostane analogues and three previously unreported derivatives with the 22,26-epoxycholesta-5,22-diene skeleton (15-17) were prepared from trillin (1), prosapogenin A of dioscin (2) and dioscin (4) by reaction with ZnCl 2/Ac 2O. Among the isolated and semisynthetic compounds, dioscin showed the most potent cytotoxicity against A549, Jurkat an…
Mimonoside D: a new triterpenoid saponin from Mimosa diplotricha Sauvalle (Fabaceae)
2021
A new triterpenoid saponin (Mimonoside D: 3-O-��-L-arabinopyranosyl-3��-hydroxyolean-12-en-28-oic acid 28-O-��-D-xylopyranosyl-(1���2)-��-D- glucopyranoside ester (1)) was isolated from the aerial parts of Mimosa diplotricha Sauvalle together with nine known compounds: 7,4���-dihydroxyflavone (2), kaempferol (3), lupeol (4), betulinic acid (5), ��-sitosterol (6), ��-sitosterol-3-O-��-D-glucopyranoside (7), lutein (8), 5,2���-dihydroxy-7,4���,5���-trimethoxyflavone (9) and vitexin (10). Their structures were elucidated on the basis of spectroscopic (1 D and 2 D nuclear magnetic resonance) and high-resolution mass spectrometric data as well as by comparison of their spectral data with those o…