Antioxidants have attracted the attention of researchers due to their beneficial effects as free radical scavengers. Application of a stable free radical named 1,1 diphenyl 2 picrylhydrazyl(DPPH) to screen the free ra...Antioxidants have attracted the attention of researchers due to their beneficial effects as free radical scavengers. Application of a stable free radical named 1,1 diphenyl 2 picrylhydrazyl(DPPH) to screen the free radical scavenging activity in 27 species of Chinese seaweed showed that 15 of them had significant activity in at least one of the organic solvent extracts. The most interesting seaweed species were Gelidium amansii, Gloiosiphonia capillaris, Polysiphonia urceolata, Sargassum kjellmanianum, Desmarestia viridis, and Rhodomela teres.展开更多
Objective:To evaluate in vitro antioxidant and antibacterial activity of methanolic extract of Arnebia benthamii（A.benthamii） whole plant.Methods:Plasmid damage was analyzed by agarose gell electrophoresis.Calf thym...Objective:To evaluate in vitro antioxidant and antibacterial activity of methanolic extract of Arnebia benthamii（A.benthamii） whole plant.Methods:Plasmid damage was analyzed by agarose gell electrophoresis.Calf thymus DNA was monitored by TBARS formation.DPPH, reducing power and lipid peroxidation was evaluated by using standard procedures.Antibacterial assay was monitored by disc diffusion method.Results:DPPH radical scavenging and hydroxyl radical scavenging potential of the plant revealed that the extract to be active radical scavenger.Reducing(Fe<sup>3+</sup>-Fe<sup>2+</sup>) power and lipid peroxidation inhibition efficiency（TBARS assay） of the extract was also evaluated and the extract showed promising activity in preventing lipid peroxidation and might prevent oxidative damages to biomolecules.The extract offered a significant protection against plasmid and calf thymus UNA damage induced by hydroxyl radicals. The extract was also evaluated on different bacterial strains and the maximum antibacterial activity was exhibited against Escherichia coli（E.coli） when compared with standard drug. Conclusions:These findings demonstrate that the methanol extract of A.benthamii has excellent anti-oxidant activities and could be considered as a potential source of lead molecules for pharmaceutical industries.展开更多
Fish skin collagen hydrolysates （FSCH） were prepared from walleye pollock （Theragra chalcogramrna） using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3...Fish skin collagen hydrolysates （FSCH） were prepared from walleye pollock （Theragra chalcogramrna） using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3%. FSCH was mainly composed of low-molecular-weight peptides and the relative proportion of 〈1000Da fraction was 70.6%. Free radical and oxygen species scavenging activities of FSCH were investigated in four model systems, including diphenylpicrylhy-drazyl radical （DPPH）, superoxide anion radical, hydroxyl radical and hydrogen peroxide model, and compared with that of a native antioxidant, reduced glutathione （GSH）. FSCH was also evaluated by water-absorbing and water-holding capacity. The results showed that FSCH was able to scavenge free radical and oxygen species significantly and to enhance water-absorbing and water-holding capacity remarkably. Therefore FSCH may have potential applications in the medicine and food industries.展开更多
In order to enhance the water-solubility and biological utilization rate of chrysin, sodium 5,7-dihydroxylflavone-8-sulfonate （1, [Na（H2O）1/2]X, X = C15H9OSO3, 5,7-dihydroxylfla- vone-8-sulfonate） was synthesized ...In order to enhance the water-solubility and biological utilization rate of chrysin, sodium 5,7-dihydroxylflavone-8-sulfonate （1, [Na（H2O）1/2]X, X = C15H9OSO3, 5,7-dihydroxylfla- vone-8-sulfonate） was synthesized and its structure was identified on the basis of NMR, FT-IR and elemental analysis. The assembly of 5,7-dihydroxylflavone-8-sulfonate with diethylamide cation afforded diethylamide 5,7-dihydroxylflavone-8-sulfonate （2, NH2（CH2CH3）2X） which was characterized by FT-IR and elemental analysis. The crystal structures of 1 and 2 were determined by X-ray single-crystal diffraction analysis. The crystal of 1 is of triclinic system, space group P1, with a = 8.5628（13）, b = 12.8916（19）, c = 13.562（2） A, α = 82.494（1）, β = 78.601（2）, γ = 84.033（2）°, C30H20Na2O15S2, Z = 2, Mr = 730.59, V = 1450.3（4） A3, Dc = 1.673 g/cm3, F（000） = 748, p = 0.295 mm^-1, the final R = 0.0641 and wR = 0.1458. The crystal of 2 crystallizes in the triclinic system, space group Pi, with a = 7.689（2）, b = 11.184（3）, c = 11.734（3） A, α = 74.268（3）, βl = 81.751（4）, γ= 87.991（3）°, C19H21NO7S, Z = 2, Mr= 407.43, V= 961.2（4） A3, Dc = 1.408 g/cm3, F（000） = 428, p = 0.210 mm^-1, the final R = 0.0484 and wR = 0.1195. In 1, the three-dimensional structure is organized into organic and inorganic regions; the flavone skeletons are stacked into organic regions by π...π staeking interactions; inorganic regions are generated by Na-O coordination bonds among sulfonate groups, coordinated water molecules and NaI. The sulfonate groups play an important role as a bridge of inorganic and organic regions. One-dimensional chain structure of 2 is extended by N-H…O hydrogen bonds and π...π stacking interactions. Furthermore, the antioxidant activity of 1 was evaluated. The scavenging activity of 1 to DPPH free radical is better than that of the parent compound chrysin.展开更多
[Objectives]To study the antioxidant activity of different solvent extracts of Gynura segetum in vitro,so as to provide experimental basis for further study and utilization of medicinal resources of G.segetum.[Methods...[Objectives]To study the antioxidant activity of different solvent extracts of Gynura segetum in vitro,so as to provide experimental basis for further study and utilization of medicinal resources of G.segetum.[Methods]The antioxidant activity of different solvent extracts of G.segetum was determined by UV-vis spectrophotometer using DPPH free radical scavenging method and ABTS^+free radical scavenging method.[Results]The scavenging rates of DPPH and ABTS^+by acetone extract were high,reaching 98.9%and 98.3%,respectively;the scavenging rate of DPPH and ABTS^+by water extract was the lowest,and the scavenging rates were 76.7%and 77.5%,respectively.The order of ABTS^+radical scavenging rate of samples extracted with different extractants was as follows:S 5(acetone extract)>S 1(ethyl acetate extract)>S 6(ethanol extract)>S 4(n-butanol extract)>S 3(methanol extract)>S 2(distilled water extract);the order of DPPH radical scavenging rate of samples extracted with different extractants was as follows:S 5(acetone extract)>S 1(ethyl acetate extract)>S 4(n-butanol extract)>S 6(ethanol extract)>S 3(methanol extract)>S 2(distilled water extract).[Conclusions]The extracts of acetone,ethyl acetate,n-butanol,anhydrous ethanol,methanol and distilled water from the roots of G.segetum had obvious scavenging effects on DPPH and ABTS^+,all had antioxidant components,and acetone had the highest antioxidant effect as an extractant.展开更多
文摘Antioxidants have attracted the attention of researchers due to their beneficial effects as free radical scavengers. Application of a stable free radical named 1,1 diphenyl 2 picrylhydrazyl(DPPH) to screen the free radical scavenging activity in 27 species of Chinese seaweed showed that 15 of them had significant activity in at least one of the organic solvent extracts. The most interesting seaweed species were Gelidium amansii, Gloiosiphonia capillaris, Polysiphonia urceolata, Sargassum kjellmanianum, Desmarestia viridis, and Rhodomela teres.
基金funded by National Medicinal Plants Board,Department of AYUSH,Ministry of Health and Family Welfare,GOI,to Dr.M.A Zargar wide grant No. Z18017-187/PR/GO/JK/04/2005-06/NMPB
文摘Objective:To evaluate in vitro antioxidant and antibacterial activity of methanolic extract of Arnebia benthamii（A.benthamii） whole plant.Methods:Plasmid damage was analyzed by agarose gell electrophoresis.Calf thymus DNA was monitored by TBARS formation.DPPH, reducing power and lipid peroxidation was evaluated by using standard procedures.Antibacterial assay was monitored by disc diffusion method.Results:DPPH radical scavenging and hydroxyl radical scavenging potential of the plant revealed that the extract to be active radical scavenger.Reducing(Fe<sup>3+</sup>-Fe<sup>2+</sup>) power and lipid peroxidation inhibition efficiency（TBARS assay） of the extract was also evaluated and the extract showed promising activity in preventing lipid peroxidation and might prevent oxidative damages to biomolecules.The extract offered a significant protection against plasmid and calf thymus UNA damage induced by hydroxyl radicals. The extract was also evaluated on different bacterial strains and the maximum antibacterial activity was exhibited against Escherichia coli（E.coli） when compared with standard drug. Conclusions:These findings demonstrate that the methanol extract of A.benthamii has excellent anti-oxidant activities and could be considered as a potential source of lead molecules for pharmaceutical industries.
基金supported by the High Technology Research and Development Program of China (No. 2006AA09Z438)the National Natural Science Foundation of China (No. 30871943).
文摘Fish skin collagen hydrolysates （FSCH） were prepared from walleye pollock （Theragra chalcogramrna） using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3%. FSCH was mainly composed of low-molecular-weight peptides and the relative proportion of 〈1000Da fraction was 70.6%. Free radical and oxygen species scavenging activities of FSCH were investigated in four model systems, including diphenylpicrylhy-drazyl radical （DPPH）, superoxide anion radical, hydroxyl radical and hydrogen peroxide model, and compared with that of a native antioxidant, reduced glutathione （GSH）. FSCH was also evaluated by water-absorbing and water-holding capacity. The results showed that FSCH was able to scavenge free radical and oxygen species significantly and to enhance water-absorbing and water-holding capacity remarkably. Therefore FSCH may have potential applications in the medicine and food industries.
基金Supported by the National Basic Research Program of China (973 Program,2009CB219906)NNSFC(20776117)+1 种基金Specialized Research Fund for the Doctoral Program of Higher Education of China(20070698037)Natural Science Foundation of Shaanxi Province (No.2005B01)
文摘In order to enhance the water-solubility and biological utilization rate of chrysin, sodium 5,7-dihydroxylflavone-8-sulfonate （1, [Na（H2O）1/2]X, X = C15H9OSO3, 5,7-dihydroxylfla- vone-8-sulfonate） was synthesized and its structure was identified on the basis of NMR, FT-IR and elemental analysis. The assembly of 5,7-dihydroxylflavone-8-sulfonate with diethylamide cation afforded diethylamide 5,7-dihydroxylflavone-8-sulfonate （2, NH2（CH2CH3）2X） which was characterized by FT-IR and elemental analysis. The crystal structures of 1 and 2 were determined by X-ray single-crystal diffraction analysis. The crystal of 1 is of triclinic system, space group P1, with a = 8.5628（13）, b = 12.8916（19）, c = 13.562（2） A, α = 82.494（1）, β = 78.601（2）, γ = 84.033（2）°, C30H20Na2O15S2, Z = 2, Mr = 730.59, V = 1450.3（4） A3, Dc = 1.673 g/cm3, F（000） = 748, p = 0.295 mm^-1, the final R = 0.0641 and wR = 0.1458. The crystal of 2 crystallizes in the triclinic system, space group Pi, with a = 7.689（2）, b = 11.184（3）, c = 11.734（3） A, α = 74.268（3）, βl = 81.751（4）, γ= 87.991（3）°, C19H21NO7S, Z = 2, Mr= 407.43, V= 961.2（4） A3, Dc = 1.408 g/cm3, F（000） = 428, p = 0.210 mm^-1, the final R = 0.0484 and wR = 0.1195. In 1, the three-dimensional structure is organized into organic and inorganic regions; the flavone skeletons are stacked into organic regions by π...π staeking interactions; inorganic regions are generated by Na-O coordination bonds among sulfonate groups, coordinated water molecules and NaI. The sulfonate groups play an important role as a bridge of inorganic and organic regions. One-dimensional chain structure of 2 is extended by N-H…O hydrogen bonds and π...π stacking interactions. Furthermore, the antioxidant activity of 1 was evaluated. The scavenging activity of 1 to DPPH free radical is better than that of the parent compound chrysin.
文摘[Objectives]To study the antioxidant activity of different solvent extracts of Gynura segetum in vitro,so as to provide experimental basis for further study and utilization of medicinal resources of G.segetum.[Methods]The antioxidant activity of different solvent extracts of G.segetum was determined by UV-vis spectrophotometer using DPPH free radical scavenging method and ABTS^+free radical scavenging method.[Results]The scavenging rates of DPPH and ABTS^+by acetone extract were high,reaching 98.9%and 98.3%,respectively;the scavenging rate of DPPH and ABTS^+by water extract was the lowest,and the scavenging rates were 76.7%and 77.5%,respectively.The order of ABTS^+radical scavenging rate of samples extracted with different extractants was as follows:S 5(acetone extract)>S 1(ethyl acetate extract)>S 6(ethanol extract)>S 4(n-butanol extract)>S 3(methanol extract)>S 2(distilled water extract);the order of DPPH radical scavenging rate of samples extracted with different extractants was as follows:S 5(acetone extract)>S 1(ethyl acetate extract)>S 4(n-butanol extract)>S 6(ethanol extract)>S 3(methanol extract)>S 2(distilled water extract).[Conclusions]The extracts of acetone,ethyl acetate,n-butanol,anhydrous ethanol,methanol and distilled water from the roots of G.segetum had obvious scavenging effects on DPPH and ABTS^+,all had antioxidant components,and acetone had the highest antioxidant effect as an extractant.
