Lotus(Nelumbo nucifera Gaertn),a kind of perennial aquatic plant,is widely cultivated and consumed by people in Asian countries.Lotus plumule flavonoids(LPF)have been recognized as a hypoglycemic agent.LPF was optimal...Lotus(Nelumbo nucifera Gaertn),a kind of perennial aquatic plant,is widely cultivated and consumed by people in Asian countries.Lotus plumule flavonoids(LPF)have been recognized as a hypoglycemic agent.LPF was optimally obtained using novel ultrasonic-microwave assisted synergistic extraction(UMSE)method by response surface methodology(RSM)on the basis of the results of single-factor experiments.Furthermore,the hypoglycemic activity of LPF was investigated by measuring the body weight,fasting blood glucose(FBG)level,and oral glucose tolerance test(OGTT)and analyzing the physiological indexes in streptozotocin-diabetic mice model.The optimum extraction conditions consisted of microwave power 355 W,ultrasonic power 423 W,extraction time 15 min,solid-liquid ratio 1:40,ultrasound/interval time 1/0,and ethanol concentration 70%with the maximum LPF yield of 2.62%.LPF supplementation significantly decreased the body weight,FBG,OGTT,serum total cholesterol(TC),serum total triglycerides(TG),and insulin levels,indicating the antidiabetic activity of LPF.This research verified that the UMSE technique was highly efficient to extract LPF to the maximum extent and the flavonoids from L.plumule exhibited hypoglycemic activity,which showed broad development and application prospects.展开更多
A technique of ultrasound-assisted low density solvent based dispersive liquid-liquid microextraction was developed for the determination of four phthalate esters, including dimethyl phthalate（DMP）, diethyl phthalat...A technique of ultrasound-assisted low density solvent based dispersive liquid-liquid microextraction was developed for the determination of four phthalate esters, including dimethyl phthalate（DMP）, diethyl phthalate（DEP）, di-n-butyl phthalate（DnBP） and di（2-ethylhexyl） phthalate（DEHP） in bottled water samples. A low density solvent, toluene, was selected as extraction solvent. In the extraction process, a mixture of 15 μL of toluene（extraction solvent） and 100 μL of methanol（disperser solvent） was rapidly injected into 1.0 mL of water samples. A cloudy solution was formed after ultrasounded for 5 min, and then centrifuged at 5000 r/min for 5 min. The enriched analytes in the floa- ting phase were determined by means of gas chromatograph. Under the optimum conditions, the enrichment factors were found to be in a range of 29--67, and the recoveries were ranged from 81.2% to 103.9%. The limits of the detection were in a range of 3.8--5.6 μg/L. The proposed method was applied to the extraction and determination of phthalate esters in bottled water samples, and the concentrations of phthalate esters found in the water samples were below the allowable levels.展开更多
基金s funded by Double First-Class Construction Plan of Fujian Agriculture and Forestry University(KSYLX013)Open Project Program(BME-202004)of Key Laboratory of Brewing Molecular Engineering of China Light Industry,Beijing 100048,China.
文摘Lotus(Nelumbo nucifera Gaertn),a kind of perennial aquatic plant,is widely cultivated and consumed by people in Asian countries.Lotus plumule flavonoids(LPF)have been recognized as a hypoglycemic agent.LPF was optimally obtained using novel ultrasonic-microwave assisted synergistic extraction(UMSE)method by response surface methodology(RSM)on the basis of the results of single-factor experiments.Furthermore,the hypoglycemic activity of LPF was investigated by measuring the body weight,fasting blood glucose(FBG)level,and oral glucose tolerance test(OGTT)and analyzing the physiological indexes in streptozotocin-diabetic mice model.The optimum extraction conditions consisted of microwave power 355 W,ultrasonic power 423 W,extraction time 15 min,solid-liquid ratio 1:40,ultrasound/interval time 1/0,and ethanol concentration 70%with the maximum LPF yield of 2.62%.LPF supplementation significantly decreased the body weight,FBG,OGTT,serum total cholesterol(TC),serum total triglycerides(TG),and insulin levels,indicating the antidiabetic activity of LPF.This research verified that the UMSE technique was highly efficient to extract LPF to the maximum extent and the flavonoids from L.plumule exhibited hypoglycemic activity,which showed broad development and application prospects.
文摘A technique of ultrasound-assisted low density solvent based dispersive liquid-liquid microextraction was developed for the determination of four phthalate esters, including dimethyl phthalate（DMP）, diethyl phthalate（DEP）, di-n-butyl phthalate（DnBP） and di（2-ethylhexyl） phthalate（DEHP） in bottled water samples. A low density solvent, toluene, was selected as extraction solvent. In the extraction process, a mixture of 15 μL of toluene（extraction solvent） and 100 μL of methanol（disperser solvent） was rapidly injected into 1.0 mL of water samples. A cloudy solution was formed after ultrasounded for 5 min, and then centrifuged at 5000 r/min for 5 min. The enriched analytes in the floa- ting phase were determined by means of gas chromatograph. Under the optimum conditions, the enrichment factors were found to be in a range of 29--67, and the recoveries were ranged from 81.2% to 103.9%. The limits of the detection were in a range of 3.8--5.6 μg/L. The proposed method was applied to the extraction and determination of phthalate esters in bottled water samples, and the concentrations of phthalate esters found in the water samples were below the allowable levels.
