Z Naturforsch C J Biosci
January 2020
The leaves of Garcinia epunctata Stapf have furnished two new phenolic glucosides, epunctosides A and B, along with 13 known secondary metabolites identified as lanceoloside A, betulinic acid, lupeol, stigmasterol, β-sitosterol, β-sitosterol-3-O-β-d-glucopyranoside, stigmasterol-3-O-β-d-glucopyranoside, luteolin-7-O-glucoside, quercitin-7-O-glucoside, amentoflavone, robustaflavone, 4'-O-methyl-amentoflavone and 4'-O-methyl-robustaflavone. All structures were established from chemical and spectroscopic evidence including 1D and 2D NMR data as well as by comparing the obtained spectroscopic data with literature. This is the first report of the presence of phenolic glucosides in the genus Garcinia.
View Article and Find Full Text PDFA novel isoflavone-chromone flavonoid C-O-C dimmer, brevipedicelone D (1), along with one new C-O-C biflavonoid derivative, brevipedicelone E (2), were isolated from the ethyl acetate extract of the leaves of Garcinia brevipedicellata, a medicinal plant used in folk medicine in parts of Cameroon. Their structures were elucidated by extensive spectroscopic techniques, including 1D- and 2D- NMR, MS experiments, as well as comparing their spectral data with those of known analogues. Anti-onchocercal screening of 1 showed moderate inhibition of adult worm motility of Onchocerca ochengi by 60% at the highest concentration (20 µg/mL) and inhibited motility of both the juvenile worms of O.
View Article and Find Full Text PDFThe methanol extract of the stem heartwood of Garcinia brevipedicellata has furnished three new flavonoid C-O-C dimers, brevipedicilones A (6), B (8) and C (10), along with five previously reported flavonoid dimers, viz. amentoflavone (1), 4″'-O-methylamentoflavone (2), robustaflavone (3), 4'-O-methyl robustaflavone (4) and tetrahinokiflavone (5). The new structures, which are composed of flavanone-flavanonol or flavanonol-flavanonol sub-units, were established based on spectroscopic analysis including 1D and 2D NMR (1H-1H COSY, HSQC, HMBC, and NOESY) spectroscopy, and by comparing their spectral data with those reported for related compounds.
View Article and Find Full Text PDFZ Naturforsch C J Biosci
January 2017
Z Naturforsch C J Biosci
September 2012
Six new compounds, comprising three flavonoid glycosides and their respective coumaroyl esters, have been isolated and characterized from the methanol extract of the leaves of Campylospermum calanthum, along with three known flavonoid aglycones, 7-O-methyl apigenin (1), 7-O-methyl luteolin (2), and 7-O-methyl quercetin (3). Their structures were elucidated based on chemical evidence as well as spectroscopic analysis including 1D and 2D NMR (1H-1H COSY, HSQC, HMBC, and NOESY) spectroscopy and by comparing their spectral data with those reported for related compounds.
View Article and Find Full Text PDFSix isoflavonoid derivatives among which three are new have been isolated from the stem heartwood of Lophira alata. The structures were elucidated from spectroscopic and chemical evidences. Two have unusual carbon skeletons, possibly resulting from a variant of isoflavonoid biogenesis.
View Article and Find Full Text PDFThe leaves of the Cameroonian medicinal plant Lophira alata afforded two new biflavonoids, lophirone L (1) and lophirone M (2), and the known luteolin and lithospermoside. Both biflavonoids were obtained in small quantities, and their structures show some new and unusual biflavonoid diversity.
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