1.Chemical Constituents of Nauclea vanderguchtii
Brice Maxime Nangmou NKOUAYEB ; Anatole Guy Blaise AZEBAZE ; Georges Bellier TABEKOUENG ; Willifred Dongmo TEKAPI TSOPGNI ; Bruno Ndjakou LENTA ; Marcel FRESE ; Norbert SEWALD ; Juliette Catherine VARDAMIDES
Natural Product Sciences 2020;26(2):144-150
Phytochemical investigation of leaves, barks and roots of Nauclea vanderguchtii led to the isolation of sixteen compounds, which includes one citric acid derivative (2), one alkaloid (16), one peptide derivative (3), and twelve triterpenes (1, 4 - 13). These compounds were identified as rotundanonic acid (1), 2-hydroxy-1,2,3-propanetricarboxylic acid 2-methyl ester (2), asperphenamate (3), lupeol (4), stigmasterol (5), betulin (6), betulenic acid (7), stigmasterol 3-O-β-D-glucopyranoside (8), quinovic acid 3β-O-α-L-rhamnoside (9), α-amyrin (10), 3-oxoquinovic acid (11), ursolic acid (12), hederagenin (13), rotundic acid (14), clethric acid (15), and naucleficine (16) by the analysis of their NMR spectroscopic data including 2D NMR spectra and by comparison of their spectroscopic data reported in the literature. Compounds 1 and 3 were isolated for the first time in the genus Nauclea, and compound 2 was isolated for the first time from the Rubiaceae family. Complete NMR assignations for 1 have been published for the first time.
2.Secondary Metabolites from Anthonotha cladantha (Harms) J.Léonard
Laurent Voufack Lefack BONGMO ; Achille Nouga BISSOUE ; Samuel Magloire BISSIM ; Georges Bellier TABEKOUENG ; Willifred Dongmo Tekapi TSOPGNI ; Mehreen LATEEF ; Félicien Mushagalusa KASALI ; Muhammad Shaiq ALI ; Alain François Kamdem WAFFO ; Jean Duplex WANSI
Natural Product Sciences 2023;29(1):50-58
The phytochemical investigation of the crude methanolic extracts roots and stem bark of Anthonotha cladantha (Harms) J.Léonard led to the isolation and identification of twelve secondary metabolites: 2,3-dihydroxypropyl hexacosanoate (1), hederagenine (2), cycloeucalenol (3), 2α-hydroxylupeol (4), betulinic acid (5), lupeol (6), heptacosan-2-one (7), triacontanoic acid (8), stigmast-4-en-3-one (9), β-sitosterol (10), stigmasterol (11), and stigmasterol-3-O-β-D-glucopyranoside (12). Their structures were elucidated with the help of their spectroscopic and physical data and by comparison with those reported in the literature. To the best of our knowledge, from all those compounds, 2,3-dihydroxypropyl hexacosanoate (1), hederagenine (2), cycloeucalenol (3), 2α-hydroxylupeol (4), and betulinic acid (5) are being reported for the first time from this genus. In addition, the acetylation of compound 1 afforded a new derivative 3-(hexacosanoyloxy)propane-1,2-diyl diacetate (1a).Compound 1 possessed a moderate α-glucosidase inhibitory activity with an IC50 value of 39.2 ± 0.22 µM; it neither showed antioxidant activity nor inhibition against the enzyme urease. Compound 1a exhibited weak antioxidant activity in the DPPH assay with an IC50 value of 80.3 ± 0.83 μM but was inactive against α-glucosidase and urease. Furthermore, both compounds 1 and 1a were inactive against seven pathogenic bacterial strains.