Five new flavan-4-ol glycosides jixueqiosides A-E(1-5)and two new flavan glycosides jixueqiosides F and G(6 and 7),along with twelve known flavan-4-ol glycosides(8-19),were isolated from the roots of Pronephrium penan...Five new flavan-4-ol glycosides jixueqiosides A-E(1-5)and two new flavan glycosides jixueqiosides F and G(6 and 7),along with twelve known flavan-4-ol glycosides(8-19),were isolated from the roots of Pronephrium penangianum.Comprehensive spectral analyses,X-ray single-crystal diffraction,and theoretical electronic circular dichroism(ECD)calculations established structures and absolute configurations.A single crystal structure of flavan-4-ol glycoside(14)was reported for the first time,while the characteristic ECD and NMR data for all isolated flavan-4-ol glycosides(1-5,8-19)were analyzed,establishing a set of empirical rules.Activity screening of these isolates showed that 8 and 9 could inhibit the proliferation of MDA-MB-231 and MCF-7 cells with IC50 values of 7.93±2.85μmol·L^(-1)and 5.87±1.58μmol·L^(-1)(MDA-MB-231),and 2.21±1.38μmol·L^(-1)and 3.52±1.55μmol·L^(-1)(MCF-7),respectively.Western blotting and flow cytometry analyses demonstrated that 8 and 9 dose-dependently induced apoptosis in MDA-MB-231 cells by up-regulating BAX,activating caspase-3 and down-regulating BCL-2.Additionally,compound 8 affected autophagy-related proteins,increasing the ratio of LC3-II/LC3-I and Beclin-1 levels to inhibit MDA-MB-231 cell proliferation.Moreover,anti-inflammatory studies indicated that 2,3,7,13,14,and 18 moderately inhibited tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),and nitric oxide(NO)release.展开更多
A new flavan-3-ol glucoside, (-)-afzelechin-7-O-β-D-glucopyranoside (1), has been isolated from the stem of Daphniphyllum oldhami. The structure of the new compound was elucidated on the basis of detailed spectroscop...A new flavan-3-ol glucoside, (-)-afzelechin-7-O-β-D-glucopyranoside (1), has been isolated from the stem of Daphniphyllum oldhami. The structure of the new compound was elucidated on the basis of detailed spectroscopie analysis and comparison with related compounds.展开更多
Although tea is grown in agro-ecological regions widely varying in environmental factors affecting yield and quality, planters usually import genetic materials across the different growing regions assuming genotypes w...Although tea is grown in agro-ecological regions widely varying in environmental factors affecting yield and quality, planters usually import genetic materials across the different growing regions assuming genotypes with good quality attributes in one location maintain their status in all regions. However, tea quality has not been replicated in new production regions. Black tea quality is influenced by the green leaf quality precursors including caffeine, total polyphenols and individual flavan-3-ols which are precursors of theaflavins and thearubigins, key plain black tea quality parameters. Factors influencing levels of the precursors compounds have not been quantified for popular Kenyan tea cultivars. The influence of geographical production location and seasons on levels and ratios of the quality precursors for 10 black tea popular clones grown in three locations in Kenya under uniform agronomic inputs were monitored. Caffeine varied significantly （P _〈 0.05） with clones and location but not with season. The flavan-3-ols and their ratios all varied （P 〈 0.05） with clones and site but not with season, with significant interactions （P 〈 0.05） between locations and clones, and locations and seasons. These results explain the observed variations in plain black tea quality due to clones and location of production. Thus, farmers in different locations are unlikely to produce black tea of same quality. It is therefore necessary to evaluate new tea genotypes in intended growing areas to establish cultivars suitable for producing high quality plain black teas in the locations. Seasonal variations in plain black tea in Kenya are unlikely to vary significantly due to flavan-3-ols.展开更多
Objective To study the chemical constituents of Pronephrium triphyllum.Methods The chemical constituents in the plant were isolated and purified with silica gel and Sephadex LH-20.Their structures were identified by a...Objective To study the chemical constituents of Pronephrium triphyllum.Methods The chemical constituents in the plant were isolated and purified with silica gel and Sephadex LH-20.Their structures were identified by analyses of spectral data and physicochemical properties.Results Six compounds were isolated and identified as shelincaoide A(1),n-butyl-β-D-fructopyranoside(2),triphyllin A(3),6,7-di-hydroxycoumarin(4),daucosterol(5),andβ-sitosterol(6),respectively.Conclusion Compound 1 is found to be a new compound.Compounds 2 and 4 are firstly isolated from the plants in Pronephrium Presl.and all compounds except 3 are obtained from the species for the first time.展开更多
基金supported by the National Natural Science Foundation of China(No.81874369)the Excellent Youth Project of the Hunan Provincial Department of Education(No.22B0388)the Project of Hunan Administration of Traditional Chinese Medicine(No.B2023143)。
文摘Five new flavan-4-ol glycosides jixueqiosides A-E(1-5)and two new flavan glycosides jixueqiosides F and G(6 and 7),along with twelve known flavan-4-ol glycosides(8-19),were isolated from the roots of Pronephrium penangianum.Comprehensive spectral analyses,X-ray single-crystal diffraction,and theoretical electronic circular dichroism(ECD)calculations established structures and absolute configurations.A single crystal structure of flavan-4-ol glycoside(14)was reported for the first time,while the characteristic ECD and NMR data for all isolated flavan-4-ol glycosides(1-5,8-19)were analyzed,establishing a set of empirical rules.Activity screening of these isolates showed that 8 and 9 could inhibit the proliferation of MDA-MB-231 and MCF-7 cells with IC50 values of 7.93±2.85μmol·L^(-1)and 5.87±1.58μmol·L^(-1)(MDA-MB-231),and 2.21±1.38μmol·L^(-1)and 3.52±1.55μmol·L^(-1)(MCF-7),respectively.Western blotting and flow cytometry analyses demonstrated that 8 and 9 dose-dependently induced apoptosis in MDA-MB-231 cells by up-regulating BAX,activating caspase-3 and down-regulating BCL-2.Additionally,compound 8 affected autophagy-related proteins,increasing the ratio of LC3-II/LC3-I and Beclin-1 levels to inhibit MDA-MB-231 cell proliferation.Moreover,anti-inflammatory studies indicated that 2,3,7,13,14,and 18 moderately inhibited tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),and nitric oxide(NO)release.
文摘A new flavan-3-ol glucoside, (-)-afzelechin-7-O-β-D-glucopyranoside (1), has been isolated from the stem of Daphniphyllum oldhami. The structure of the new compound was elucidated on the basis of detailed spectroscopie analysis and comparison with related compounds.
文摘Although tea is grown in agro-ecological regions widely varying in environmental factors affecting yield and quality, planters usually import genetic materials across the different growing regions assuming genotypes with good quality attributes in one location maintain their status in all regions. However, tea quality has not been replicated in new production regions. Black tea quality is influenced by the green leaf quality precursors including caffeine, total polyphenols and individual flavan-3-ols which are precursors of theaflavins and thearubigins, key plain black tea quality parameters. Factors influencing levels of the precursors compounds have not been quantified for popular Kenyan tea cultivars. The influence of geographical production location and seasons on levels and ratios of the quality precursors for 10 black tea popular clones grown in three locations in Kenya under uniform agronomic inputs were monitored. Caffeine varied significantly （P _〈 0.05） with clones and location but not with season. The flavan-3-ols and their ratios all varied （P 〈 0.05） with clones and site but not with season, with significant interactions （P 〈 0.05） between locations and clones, and locations and seasons. These results explain the observed variations in plain black tea quality due to clones and location of production. Thus, farmers in different locations are unlikely to produce black tea of same quality. It is therefore necessary to evaluate new tea genotypes in intended growing areas to establish cultivars suitable for producing high quality plain black teas in the locations. Seasonal variations in plain black tea in Kenya are unlikely to vary significantly due to flavan-3-ols.
基金Science and Technology Project of Zhongshan,China(20071A036)
文摘Objective To study the chemical constituents of Pronephrium triphyllum.Methods The chemical constituents in the plant were isolated and purified with silica gel and Sephadex LH-20.Their structures were identified by analyses of spectral data and physicochemical properties.Results Six compounds were isolated and identified as shelincaoide A(1),n-butyl-β-D-fructopyranoside(2),triphyllin A(3),6,7-di-hydroxycoumarin(4),daucosterol(5),andβ-sitosterol(6),respectively.Conclusion Compound 1 is found to be a new compound.Compounds 2 and 4 are firstly isolated from the plants in Pronephrium Presl.and all compounds except 3 are obtained from the species for the first time.
