A convenient one-pot synthesis of functionalized (E)-2-arylvinyl bromides was achieved by microwave-induced deacetylation and subsequent acylation using dicyclohexyl carbodiimide (DCC) and dimethylamino-pyridine ...A convenient one-pot synthesis of functionalized (E)-2-arylvinyl bromides was achieved by microwave-induced deacetylation and subsequent acylation using dicyclohexyl carbodiimide (DCC) and dimethylamino-pyridine (DMAP) at room temperature from (E)-4-(2-bromovinyl)phenyl acetate.展开更多
A synthetic cationic surfactant, 5,5-ditetradecyl-2-(2-trimethyl-ammonioethyl)-1,3-dioxane bromide (DTDB), was used to construct a supported bilayer lipid membrane (s-BLM) coated on an underlying glassy carbon electro...A synthetic cationic surfactant, 5,5-ditetradecyl-2-(2-trimethyl-ammonioethyl)-1,3-dioxane bromide (DTDB), was used to construct a supported bilayer lipid membrane (s-BLM) coated on an underlying glassy carbon electrode (GCE). Electrochemical impedance spectroscopy (EIS), small-angle X-ray diffraction (SAXD) and cyclic voltammetry were used to characterize the s-BLM. Both EIS and SAXD data indicated that the synthetic lipid exists as a well-oriented bilayer in the membrane. The voltammetric study showed that the lipid membrane can open ion channels in the presence of C1O4- stimulant with Ru(bpy)32+ as marker ions and give distinct channel currents. The channels can be closed and open up again many times by removing or introducing ClO4- anions.展开更多
A novel method for the determination of cationic surfactant by laser thermal lens spectrometry was developed. It was based on the reaction between 1-hydroxy-2-(5-nitro-2-Pyri- dylazo)-8-aminonaphthalene-3,6-disulfoni...A novel method for the determination of cationic surfactant by laser thermal lens spectrometry was developed. It was based on the reaction between 1-hydroxy-2-(5-nitro-2-Pyri- dylazo)-8-aminonaphthalene-3,6-disulfonic acid (5-NO2-PAH) and cationic surfactant to form 1:2 ionic association complex in a weakly basic medium (pH 9.44). The determination conditions and the mechanism were discussed. The method has been applied to the analysis of wastewater and moat water samples.展开更多
This study is designed to evaluate antioxidant and antigenotoxic activities of corn tassel extracts(CTTs). The major bioactive components of CTTs include flavonoid, saponin and polysaccharide. The antioxidant proper...This study is designed to evaluate antioxidant and antigenotoxic activities of corn tassel extracts(CTTs). The major bioactive components of CTTs include flavonoid, saponin and polysaccharide. The antioxidant properties of the three bioactive components of CTTs were investigated by Ferric Reducing Antioxidant Property(FRAP) and 1, 1-diphenyl-2-picrylhydrazyl(DPPH) assays. The activities of the extracts were determined by assessing the inhibition of mutagenicity of the direct-acting mutagen fenaminosulf, sodium azide, and indirect-acting mutagen 2-aminofluorene using the Ames test(strains TA98 and TA100). The results showed that the extraction rates of flavonoid, saponin, and polysaccharide from the dried corn tassels were 1.67%, 2.41% and 4.76% respectively. DPPH and FRAP assay strongly demonstrated that CTTs had antioxidant properties. CTTs at doses of 625, 1250 and 2500 μg per plate reduced 2-aminofluorene mutagenicity by 12.52%, 28.76% and 36.49% in Salmonella typhimurium TA98 strain assay respectively and by 10.98%, 25.27% and 37.83%, at the same doses in Salmonella typhimurium TA100 assay system, respectively. 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide(MTT) assay showed that the different concentrations of CTTs inhibited the proliferation of MGC80-3 cells in a dose-dependent manner(P0.01). It is concluded that these integrated approaches to antioxidant and antigenotoxicity assessment may be useful to study corn tassel as a natural herbal material.展开更多
In order to Isolate anti-human Immunodeflclency virus (HIV) agents from natural products, 97 ethanollc extracts of 90 fungi were tested for their Inhibitory activity on HIV-1. Most of the extracts tested were relati...In order to Isolate anti-human Immunodeflclency virus (HIV) agents from natural products, 97 ethanollc extracts of 90 fungi were tested for their Inhibitory activity on HIV-1. Most of the extracts tested were relatively non-toxic to human lymphocytic MT-4 cells, but extracts of some fungi exhibited potent antl-HIV activity In an in vitro 3-(4, 5-dlmethyl-2 thlazoyl)-2,5-dlphenyl-2H-tetrazollum bromide assay with a selectivity Index greater than 3. Most fungi were Isolated from Dendrobium sp. and Taxus sp.展开更多
Objective:To investigate the anticancer activity of the total flavonoids isolated from a herbal formula,Xianhe Yanling Recipe(仙鹤延龄方),a recipe commonly used in cancer patients in China.Methods: The in vitro an...Objective:To investigate the anticancer activity of the total flavonoids isolated from a herbal formula,Xianhe Yanling Recipe(仙鹤延龄方),a recipe commonly used in cancer patients in China.Methods: The in vitro anticancer activity of the total flavonoids was determined using the 3-(4,5-dimethylthiazole-2-yl)-2,5- diphenyltetrazolium bromide(MTT) assay on three cancer cell lines:MCF-7(a human breast adenocarcinoma cell line),HepG-2(a human hepatocellular carcinoma cell line) and ES-2(a human ovarian cancer cell line). The in vivo anticancer effect of the total flavonoids was assessed in a mouse tumor model bearing H22-induced hepatocellular carcinoma,and cisplatin was used as a positive control.Results:The total flavonoids exerted a powerful inhibitory effect on the three cell lines,with 50%inhibiting concentrations(IC_(50)) of 24.948,31.569 and 6.923μg/mL,respectively.In vivo studies showed that the total flavonoids had dose-dependent inhibitory effects on hepatocellular carcinoma in mice.Conclusion:The total flavonoids from Xianhe Yanling Recipe have potential anticancer activity,and further researches and development are warranted.展开更多
基金supported by the Natural Science Foundation of Shanghai,China(No.06ZR14085)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry.
文摘A convenient one-pot synthesis of functionalized (E)-2-arylvinyl bromides was achieved by microwave-induced deacetylation and subsequent acylation using dicyclohexyl carbodiimide (DCC) and dimethylamino-pyridine (DMAP) at room temperature from (E)-4-(2-bromovinyl)phenyl acetate.
基金Project supported by University of Science and Technology of China(Nos.ky1212 and ky2216).
文摘A synthetic cationic surfactant, 5,5-ditetradecyl-2-(2-trimethyl-ammonioethyl)-1,3-dioxane bromide (DTDB), was used to construct a supported bilayer lipid membrane (s-BLM) coated on an underlying glassy carbon electrode (GCE). Electrochemical impedance spectroscopy (EIS), small-angle X-ray diffraction (SAXD) and cyclic voltammetry were used to characterize the s-BLM. Both EIS and SAXD data indicated that the synthetic lipid exists as a well-oriented bilayer in the membrane. The voltammetric study showed that the lipid membrane can open ion channels in the presence of C1O4- stimulant with Ru(bpy)32+ as marker ions and give distinct channel currents. The channels can be closed and open up again many times by removing or introducing ClO4- anions.
文摘A novel method for the determination of cationic surfactant by laser thermal lens spectrometry was developed. It was based on the reaction between 1-hydroxy-2-(5-nitro-2-Pyri- dylazo)-8-aminonaphthalene-3,6-disulfonic acid (5-NO2-PAH) and cationic surfactant to form 1:2 ionic association complex in a weakly basic medium (pH 9.44). The determination conditions and the mechanism were discussed. The method has been applied to the analysis of wastewater and moat water samples.
基金supported by the National Natural Science Foundation of China(No.21077082)
文摘This study is designed to evaluate antioxidant and antigenotoxic activities of corn tassel extracts(CTTs). The major bioactive components of CTTs include flavonoid, saponin and polysaccharide. The antioxidant properties of the three bioactive components of CTTs were investigated by Ferric Reducing Antioxidant Property(FRAP) and 1, 1-diphenyl-2-picrylhydrazyl(DPPH) assays. The activities of the extracts were determined by assessing the inhibition of mutagenicity of the direct-acting mutagen fenaminosulf, sodium azide, and indirect-acting mutagen 2-aminofluorene using the Ames test(strains TA98 and TA100). The results showed that the extraction rates of flavonoid, saponin, and polysaccharide from the dried corn tassels were 1.67%, 2.41% and 4.76% respectively. DPPH and FRAP assay strongly demonstrated that CTTs had antioxidant properties. CTTs at doses of 625, 1250 and 2500 μg per plate reduced 2-aminofluorene mutagenicity by 12.52%, 28.76% and 36.49% in Salmonella typhimurium TA98 strain assay respectively and by 10.98%, 25.27% and 37.83%, at the same doses in Salmonella typhimurium TA100 assay system, respectively. 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide(MTT) assay showed that the different concentrations of CTTs inhibited the proliferation of MGC80-3 cells in a dose-dependent manner(P0.01). It is concluded that these integrated approaches to antioxidant and antigenotoxicity assessment may be useful to study corn tassel as a natural herbal material.
基金National Medicine Science Foundation during the 10th Five-Year Plan Period (2001BA705B01) and the National Science Fund for Distinguished Young Scholars (30325047).
文摘In order to Isolate anti-human Immunodeflclency virus (HIV) agents from natural products, 97 ethanollc extracts of 90 fungi were tested for their Inhibitory activity on HIV-1. Most of the extracts tested were relatively non-toxic to human lymphocytic MT-4 cells, but extracts of some fungi exhibited potent antl-HIV activity In an in vitro 3-(4, 5-dlmethyl-2 thlazoyl)-2,5-dlphenyl-2H-tetrazollum bromide assay with a selectivity Index greater than 3. Most fungi were Isolated from Dendrobium sp. and Taxus sp.
文摘Objective:To investigate the anticancer activity of the total flavonoids isolated from a herbal formula,Xianhe Yanling Recipe(仙鹤延龄方),a recipe commonly used in cancer patients in China.Methods: The in vitro anticancer activity of the total flavonoids was determined using the 3-(4,5-dimethylthiazole-2-yl)-2,5- diphenyltetrazolium bromide(MTT) assay on three cancer cell lines:MCF-7(a human breast adenocarcinoma cell line),HepG-2(a human hepatocellular carcinoma cell line) and ES-2(a human ovarian cancer cell line). The in vivo anticancer effect of the total flavonoids was assessed in a mouse tumor model bearing H22-induced hepatocellular carcinoma,and cisplatin was used as a positive control.Results:The total flavonoids exerted a powerful inhibitory effect on the three cell lines,with 50%inhibiting concentrations(IC_(50)) of 24.948,31.569 and 6.923μg/mL,respectively.In vivo studies showed that the total flavonoids had dose-dependent inhibitory effects on hepatocellular carcinoma in mice.Conclusion:The total flavonoids from Xianhe Yanling Recipe have potential anticancer activity,and further researches and development are warranted.