Grape seeds are rich sources of procyanidin(PCs)known for potential health benefi ts.In this study,PCs were extracted from defatted grape seeds by enzymatic method in which pectinase and cellulase were used.The enzyme...Grape seeds are rich sources of procyanidin(PCs)known for potential health benefi ts.In this study,PCs were extracted from defatted grape seeds by enzymatic method in which pectinase and cellulase were used.The enzyme extraction process was further optimized by single factor experiment and response surface methodology.The optimal conditions were as follows:ethanol concentration of 70%,extraction time of 70 min,extraction temperature of 35℃,liquid/solid ratio of 103:1(mL/g),pectinase/cellulase ratio of 1:1,enzyme/solid ratio of 1:314 w/w.Under the above conditions,the extraction yields and mean degree of polymerisation(mDP)of PCs reached 47.18 mg/g dry material weight and 11.2,respectively.Compared with other extraction methods,enzyme extraction can obtain PCs with higher yield and lower mDP.According to the antioxidant activity test,PCs extracts with lower mDP showed better ability to clear 1,1-Diphenyl-2-picrylhydrazyl radical(DPPH).Enzymatic extraction was an effi cient method to obtain oligomeric procyanidin which has stronger antioxidant activity.展开更多
In this work, a fluorescein-derived fluorescent probe for H2S based on the thiolysis of dinitrophenyl ether is reported. This probe exhibits turn-on fluorescence imaging of H2S in living cells and bulk solutions with ...In this work, a fluorescein-derived fluorescent probe for H2S based on the thiolysis of dinitrophenyl ether is reported. This probe exhibits turn-on fluorescence imaging of H2S in living cells and bulk solutions with excellent selectivity. The reaction mechanism was explained by means of absorption, fluorescence and HPLC-MS.展开更多
文摘Grape seeds are rich sources of procyanidin(PCs)known for potential health benefi ts.In this study,PCs were extracted from defatted grape seeds by enzymatic method in which pectinase and cellulase were used.The enzyme extraction process was further optimized by single factor experiment and response surface methodology.The optimal conditions were as follows:ethanol concentration of 70%,extraction time of 70 min,extraction temperature of 35℃,liquid/solid ratio of 103:1(mL/g),pectinase/cellulase ratio of 1:1,enzyme/solid ratio of 1:314 w/w.Under the above conditions,the extraction yields and mean degree of polymerisation(mDP)of PCs reached 47.18 mg/g dry material weight and 11.2,respectively.Compared with other extraction methods,enzyme extraction can obtain PCs with higher yield and lower mDP.According to the antioxidant activity test,PCs extracts with lower mDP showed better ability to clear 1,1-Diphenyl-2-picrylhydrazyl radical(DPPH).Enzymatic extraction was an effi cient method to obtain oligomeric procyanidin which has stronger antioxidant activity.
基金the National Natural Science Foundation of China(No.21276251)Ministry of Human Resources and Social Security of PRC+1 种基金the 100 talents program funded by Chinese Academy of SciencesState Key Laboratory of Fine Chemicals of China(No.KF1105)
文摘In this work, a fluorescein-derived fluorescent probe for H2S based on the thiolysis of dinitrophenyl ether is reported. This probe exhibits turn-on fluorescence imaging of H2S in living cells and bulk solutions with excellent selectivity. The reaction mechanism was explained by means of absorption, fluorescence and HPLC-MS.
