A new flavonol glycoside, 5,7,3,4 tetrahydroxy 3 methoxyflavonol 3 O β D glucopyranoside(1) was isolated along with quercetin(2), quercetin 3 O α L rhamnopyranoside(3), quercetin 3 O β D ...A new flavonol glycoside, 5,7,3,4 tetrahydroxy 3 methoxyflavonol 3 O β D glucopyranoside(1) was isolated along with quercetin(2), quercetin 3 O α L rhamnopyranoside(3), quercetin 3 O β D glucopyranoside(4) and kaempferol 3 O β D (6' O p coumaroyl) glucopyranoside(5) from Anaphalis sinica Hance. Their structures were determined on the basis of spectral data(MS, UV, IR, 1H and 13 C NMR). The structure of compound 1 was confirmed by X ray crystallographic analysis.展开更多
Glycyrrhetic acid 3-O-mono-β-D-glucuronide （GAMG）, the major functional ingredient in licorice, has widespread applications in food, pharmacy and cosmetics industry. The production of GAMG through Penicillium purpu...Glycyrrhetic acid 3-O-mono-β-D-glucuronide （GAMG）, the major functional ingredient in licorice, has widespread applications in food, pharmacy and cosmetics industry. The production of GAMG through Penicillium purpurogenum Li-3 cultivation was for the first time performed through both batch and fed-batch processes in bioreactors. In batch process, under optimal conditions （pH 5.0, temperature 32℃, agitation speed 100 r. rain 1）, 3.55 g. L^-1 GAMG was obtained in a 2.5 L fermentor. To further enhance GAMG production, a fine fed-batch process was developed by using pH and DO as feedback parameters. Starting from 48 h, 100 m190 g-L 1 substrate Glycyrrhizin （GL） was fed each time when pH increased to above 5.0 and DO was increased to above 80%. This strategy can significantly enhance GAMG production： the achieved GL conversion was 95.34% with GAMG yield of 95.15%, and GAMG concentration was 16.62 g. L^-1 which was 5 times higher than that of batch. Then, a two-step separation strat- egy was established to separate GAMG from fermentation broth by crude extraction of 15 ml column packed with D10I resin followed by fine purification with preparative C18 chromatography. The obtained GAMG purity was 95.79%. This study provides a new insight into the industrial bioprocess of high-level GAMG production.展开更多
Distinguished from commonly used Fe2O3 and Fe3O4,a three-dimensional multilevel macromicro-mesoporous structure of FeC2O4/graphene composite has been prepared as binderfree electrode for supercapacitors.The as-prepare...Distinguished from commonly used Fe2O3 and Fe3O4,a three-dimensional multilevel macromicro-mesoporous structure of FeC2O4/graphene composite has been prepared as binderfree electrode for supercapacitors.The as-prepared materials are composed of macroporous graphene and microporous/mesoporous ferrous oxalate.Generally,the decomposition voltage of water is 1.23 V and the practical voltage window limit is about 2 V for asymmetric supercapacitors in aqueous electrolytes.When FeC2O4/rGO hydrogel was used as the negative electrode and a pure rGO hydrogel was used as the positive electrode,the asymmetrical supercapacitor voltage window raised to 1.7 V in KOH(1.0 mol/L)electrolyte and reached up to 2.5 V in a neutral aqueous Na2SO4(1.0 mol/L)electrolyte.Correspondingly it also exhibits a high performance with an energy density of 59.7 Wh/kg.By means of combining a metal oxide that owns micro-mesoporous structure with graphene,this work provides a new opportunity for preparing high-voltage aqueous asymmetric supercapacitors without addition of conductive agent and binder.展开更多
In the stratosphere, CF3Cl（ CFC 13 ） can either photodecompose or react directly with atomic oxygen to generate ozone-depleting agents such as Cl and ClO in the gas phase. Since the 1970s, attention has been focused...In the stratosphere, CF3Cl（ CFC 13 ） can either photodecompose or react directly with atomic oxygen to generate ozone-depleting agents such as Cl and ClO in the gas phase. Since the 1970s, attention has been focused on the effects of these compounds on the destruction of ozone in the stratosphere and on global warming. Takahashi and coworkers detected ClO radicals and measured the product branching ratios of the title reaction system via the technique of vacuum ultraviolet laser-induced fluorescence. Yu and coworkers studied the mechanisms of the title reaction induced by the photolysis of the CF3Cl-O3 system at 253.7 nm.展开更多
文摘A new flavonol glycoside, 5,7,3,4 tetrahydroxy 3 methoxyflavonol 3 O β D glucopyranoside(1) was isolated along with quercetin(2), quercetin 3 O α L rhamnopyranoside(3), quercetin 3 O β D glucopyranoside(4) and kaempferol 3 O β D (6' O p coumaroyl) glucopyranoside(5) from Anaphalis sinica Hance. Their structures were determined on the basis of spectral data(MS, UV, IR, 1H and 13 C NMR). The structure of compound 1 was confirmed by X ray crystallographic analysis.
基金Supported by the National Natural Science Foundation of China(21176028 and21506011)the National Science Fund for Distinguished Young Scholars of China(21425624)Doctoral Fund of Ministry of Education of China(20121101110050)
文摘Glycyrrhetic acid 3-O-mono-β-D-glucuronide （GAMG）, the major functional ingredient in licorice, has widespread applications in food, pharmacy and cosmetics industry. The production of GAMG through Penicillium purpurogenum Li-3 cultivation was for the first time performed through both batch and fed-batch processes in bioreactors. In batch process, under optimal conditions （pH 5.0, temperature 32℃, agitation speed 100 r. rain 1）, 3.55 g. L^-1 GAMG was obtained in a 2.5 L fermentor. To further enhance GAMG production, a fine fed-batch process was developed by using pH and DO as feedback parameters. Starting from 48 h, 100 m190 g-L 1 substrate Glycyrrhizin （GL） was fed each time when pH increased to above 5.0 and DO was increased to above 80%. This strategy can significantly enhance GAMG production： the achieved GL conversion was 95.34% with GAMG yield of 95.15%, and GAMG concentration was 16.62 g. L^-1 which was 5 times higher than that of batch. Then, a two-step separation strat- egy was established to separate GAMG from fermentation broth by crude extraction of 15 ml column packed with D10I resin followed by fine purification with preparative C18 chromatography. The obtained GAMG purity was 95.79%. This study provides a new insight into the industrial bioprocess of high-level GAMG production.
基金supported by the National Natural Science Foundation of China (No.51673180 and No. 51673180)
文摘Distinguished from commonly used Fe2O3 and Fe3O4,a three-dimensional multilevel macromicro-mesoporous structure of FeC2O4/graphene composite has been prepared as binderfree electrode for supercapacitors.The as-prepared materials are composed of macroporous graphene and microporous/mesoporous ferrous oxalate.Generally,the decomposition voltage of water is 1.23 V and the practical voltage window limit is about 2 V for asymmetric supercapacitors in aqueous electrolytes.When FeC2O4/rGO hydrogel was used as the negative electrode and a pure rGO hydrogel was used as the positive electrode,the asymmetrical supercapacitor voltage window raised to 1.7 V in KOH(1.0 mol/L)electrolyte and reached up to 2.5 V in a neutral aqueous Na2SO4(1.0 mol/L)electrolyte.Correspondingly it also exhibits a high performance with an energy density of 59.7 Wh/kg.By means of combining a metal oxide that owns micro-mesoporous structure with graphene,this work provides a new opportunity for preparing high-voltage aqueous asymmetric supercapacitors without addition of conductive agent and binder.
基金Supported by the National Natural Science Foundation of China(Nos. 20573064, 20073024) and the Special PhD Foundationof Ministry of Education of P. R. China(No. 20020422027).
文摘In the stratosphere, CF3Cl（ CFC 13 ） can either photodecompose or react directly with atomic oxygen to generate ozone-depleting agents such as Cl and ClO in the gas phase. Since the 1970s, attention has been focused on the effects of these compounds on the destruction of ozone in the stratosphere and on global warming. Takahashi and coworkers detected ClO radicals and measured the product branching ratios of the title reaction system via the technique of vacuum ultraviolet laser-induced fluorescence. Yu and coworkers studied the mechanisms of the title reaction induced by the photolysis of the CF3Cl-O3 system at 253.7 nm.
