The influence of five extraction processes(ultrasound-assisted extraction,acid extraction,enzymatic extraction,hot water extraction,hot alcohol extraction)on the total flavonoids(TF)from Hypericum benthamii was investigate by single factor and response surface experiments,with the distribution and content of major flavonoid glycosides determined and analyzed by HPLC.The correlation between TF and in vitro antioxidant activity[1,1-diphenyl-2-trinitrophenylhydrazine free radical(DPPH·)scavenging ability,2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt(ABTS·)scavenging ability,·OH scavenging ability,reducing ability]along with its in vitro hypoglycemic ability to α-glucosidase were further investigated.The results showed that ultrasound-assisted extraction achieved the highest TF content,and the best extraction process optimized by response surface experiment was obtained.Under the conditions of ultrasonic extraction temperature 68 ℃,extraction time 23 min,ethanol volume fraction 24％,liquid to material ratio of solvent to sample(mL∶g)63∶1,the TF content reached 34.85 mg RT/g[Equivalent rutin(RT)mass per gram of TF compound expressed].Seven major flavonoids in TF was identified by HPLC,with the most abundant flavonoid compounds of quercetin-3-O-palmitoyl-7-O-rhamnoside with 3.897 mg/g and quercetin with 2.874 mg/g.There was a significant positive correlation between TF mass concentration and DPPH·scavenging ability,ABTS·scavenging ability,·OH scavenging ability and reducing ability.The hypoglycemic capacity of TF to α-glucosidase could reach 92.6％.
关键词
弯萼金丝桃/总黄酮/提取工艺/高效液相色谱/抗氧化活性/降糖活性/中药现代化技术
Key words
Hypericum benthamii/total flavonoids/extraction process/HPLC/antioxidant activity/hypoglycemic activity/modernization technology of traditional Chinese medicines
维普
万方数据