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
Excess molar volumes (V^E_m) of binary mixtures of2-methyl-3-buten-3-ol [CH_3C(OH)(CH_3)CHCG_2] with four 1-alcohols:methanol, ethanol, 1-propanol and l-butanol at 298.15 K andatmospheric pressure are derived from den...Excess molar volumes (V^E_m) of binary mixtures of2-methyl-3-buten-3-ol [CH_3C(OH)(CH_3)CHCG_2] with four 1-alcohols:methanol, ethanol, 1-propanol and l-butanol at 298.15 K andatmospheric pressure are derived from density measurements with avibrating-tube densimeter. All the excess volumes are negative in thesystems over the entire composition range. The results are correlatedwith the Redlich-Kister equation. The effects of chain length ofl-alcohols on V^E_m are discussed. The apparent molar volumes of2-methyl-3-ol and l-alcohols are calculated respectively.展开更多
Objective:To investigate the estrogenic effect of(8,9)-furanyl-pterocarpan-3-ol(FPC)on growth of human breast cancer T47D cells and the interactions between the FPC and tamoxifen(TAM),on the growth of estrogen recepto...Objective:To investigate the estrogenic effect of(8,9)-furanyl-pterocarpan-3-ol(FPC)on growth of human breast cancer T47D cells and the interactions between the FPC and tamoxifen(TAM),on the growth of estrogen receptor-dependent breast cancer T47D cells.Methods:The proliferation effect of FPC were conducted on T47D cells in vitro by MTT test.T47D cells were treated with FPC alone(0.01-200μmol/L)or in combination with TAM 20 nmol/L.Furthermore,the expression of ERαor c-Myc were also determined by immunohistochemistry.Results:The results indicated that administration of an anti-estrogen TAM showed growth inhibitory effect on T47D cells,wheraes co-administered with low concentration(less than 1μmol/L)of FPC attenuated to promote cell proliferation.In contrast,the combination of TAM with higher doses(more than 20μmol/L)of FPC showed growth inhibitory.This result was supported by immunocytochemistry studies that the administration of 20 nmol/L TAM down-regulated ER-αand c-Myc,but the combination of 20 nmol/L TAM and 1μmol/L FPC robustly up-regulated expression of ER-α.Thus,the reduced growth inhibition of TAM 20 nmol/L by FPC 1μmol/L on T47D cells may act via the modulation of ER-α.Conclusions:The findings indicate and suggest that FPC had estrogenic activity at low concentrations and anti-estrogenic effect that are likely to be regulated by c-Myc and estrogen receptors.We also confirm that low concentration of FPC attenuated the growth-inhibitory effects of TAM on mammary tumor prevention.Therefore,the present study suggests that caution is warranted regarding the consumption of dietary FPC by breast cancer patients while on TMA therapy.展开更多
acetoxy-17,17-ethylendioxy-15β,16β-methylene-5-androsten-7β-ol（Ⅰ） was prepared by 3 steps from 3β-acetoxy-15β,16β-methylene-5-androsten-17-one （Ⅱ） with overall yield of 52.7%. Thus, interaction of ethylene...acetoxy-17,17-ethylendioxy-15β,16β-methylene-5-androsten-7β-ol（Ⅰ） was prepared by 3 steps from 3β-acetoxy-15β,16β-methylene-5-androsten-17-one （Ⅱ） with overall yield of 52.7%. Thus, interaction of ethylene glycol and material （Ⅱ） gave 3β-acetoxy- 17,17-ethylendioxy-15β,16β-methylene-5-androsten （Ⅲ） which was subsequently oxidated and stereoselectively reduced to produce compound（Ⅰ）. The normal influencing factors, such as the types of oxidants and reductives, the mole ratio of reactants, the reaction temperature, and the addition ways of reactants, in oxidation and reduction were discussed. The results show that the oxidation rate order is CrO3-C5H5N （1∶1, mole fraction）>CrO3-C5H5N（1∶2）>（C5H5NH）2Cr2O7 in terms of the oxidant, the yield of the oxidation becomes higher with increasing the oxidant stoichiometry and raising the reaction temperature. And the optimum condition is that the reaction temperature is at 30 ℃, and n （Ⅲ）/ n （CrO3-C5H5N（1∶2））=1∶20. The yield of the -7β alcohol order with Li[Al（OC（CH3）3）3H] （e.g.78.6%） is more than that with NaBH4 （e.g.14.5%） in terms of the reductive （agent） and the reduction rate decreases in the course of reaction. The compound （Ⅰ） is characterized by IR and MS.展开更多
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Supported by the National Natural Science Foundation of China (No. 29976035).
文摘Excess molar volumes (V^E_m) of binary mixtures of2-methyl-3-buten-3-ol [CH_3C(OH)(CH_3)CHCG_2] with four 1-alcohols:methanol, ethanol, 1-propanol and l-butanol at 298.15 K andatmospheric pressure are derived from density measurements with avibrating-tube densimeter. All the excess volumes are negative in thesystems over the entire composition range. The results are correlatedwith the Redlich-Kister equation. The effects of chain length ofl-alcohols on V^E_m are discussed. The apparent molar volumes of2-methyl-3-ol and l-alcohols are calculated respectively.
基金Supported in part by Hibah Competition Grant Research of Faculty of PharmacyGadjah Mada University(Grant No.UGM/FA/851.d/M/05/01)
文摘Objective:To investigate the estrogenic effect of(8,9)-furanyl-pterocarpan-3-ol(FPC)on growth of human breast cancer T47D cells and the interactions between the FPC and tamoxifen(TAM),on the growth of estrogen receptor-dependent breast cancer T47D cells.Methods:The proliferation effect of FPC were conducted on T47D cells in vitro by MTT test.T47D cells were treated with FPC alone(0.01-200μmol/L)or in combination with TAM 20 nmol/L.Furthermore,the expression of ERαor c-Myc were also determined by immunohistochemistry.Results:The results indicated that administration of an anti-estrogen TAM showed growth inhibitory effect on T47D cells,wheraes co-administered with low concentration(less than 1μmol/L)of FPC attenuated to promote cell proliferation.In contrast,the combination of TAM with higher doses(more than 20μmol/L)of FPC showed growth inhibitory.This result was supported by immunocytochemistry studies that the administration of 20 nmol/L TAM down-regulated ER-αand c-Myc,but the combination of 20 nmol/L TAM and 1μmol/L FPC robustly up-regulated expression of ER-α.Thus,the reduced growth inhibition of TAM 20 nmol/L by FPC 1μmol/L on T47D cells may act via the modulation of ER-α.Conclusions:The findings indicate and suggest that FPC had estrogenic activity at low concentrations and anti-estrogenic effect that are likely to be regulated by c-Myc and estrogen receptors.We also confirm that low concentration of FPC attenuated the growth-inhibitory effects of TAM on mammary tumor prevention.Therefore,the present study suggests that caution is warranted regarding the consumption of dietary FPC by breast cancer patients while on TMA therapy.
文摘acetoxy-17,17-ethylendioxy-15β,16β-methylene-5-androsten-7β-ol（Ⅰ） was prepared by 3 steps from 3β-acetoxy-15β,16β-methylene-5-androsten-17-one （Ⅱ） with overall yield of 52.7%. Thus, interaction of ethylene glycol and material （Ⅱ） gave 3β-acetoxy- 17,17-ethylendioxy-15β,16β-methylene-5-androsten （Ⅲ） which was subsequently oxidated and stereoselectively reduced to produce compound（Ⅰ）. The normal influencing factors, such as the types of oxidants and reductives, the mole ratio of reactants, the reaction temperature, and the addition ways of reactants, in oxidation and reduction were discussed. The results show that the oxidation rate order is CrO3-C5H5N （1∶1, mole fraction）>CrO3-C5H5N（1∶2）>（C5H5NH）2Cr2O7 in terms of the oxidant, the yield of the oxidation becomes higher with increasing the oxidant stoichiometry and raising the reaction temperature. And the optimum condition is that the reaction temperature is at 30 ℃, and n （Ⅲ）/ n （CrO3-C5H5N（1∶2））=1∶20. The yield of the -7β alcohol order with Li[Al（OC（CH3）3）3H] （e.g.78.6%） is more than that with NaBH4 （e.g.14.5%） in terms of the reductive （agent） and the reduction rate decreases in the course of reaction. The compound （Ⅰ） is characterized by IR and MS.
