Study On Extraction Of Flavonoids And Antioxidant Activity Of The Extracts From Ampelopsis Grossedentata

Ampelopsis grossedentata, commonly known as vine tea, belongs to the genus AmpelopsisMichx and the family Victacea. The stem and leaf of ampelopsis grossedentata is a wild plantresource that has great developmental potential. This article will conduct an in-depth study onoptimizing two ways of extracting ampelopsis grossedentata flavonoids as well as systemicallyexamining the antioxidant activity of different solvent extracts of ampelopsis grossedentata. Thearticle will also investigate and summarize the correlation between its antioxidant activity and itsflavonoids content. The main contents are as follows:1、Ultrasonic Extraction ProcessEthanol was found to be the most suitable solvent for the extraction of flavonoid compoundsfrom ampelopsis grossedentata when using the percent yield of extraction as the standard index.One-factor experimental design was utilized and the following parameters were found to result inthe highest percent yield of flavonoid compounds extracts: liquid to solid ratio25:1~35:1;ultrasonic temperature58℃~72℃; ethanol concentration65%~75%; ultrasonic time35min~45min; ultrasonic power240w; grinding particle size60μm.On the basis of one-factor experiment, four most influential parameters (liquid to solid ratio,ultrasonic temperature, ethanol concentration, and ultrasonic time) were selected and analyzedusing response surface methodology to optimize the ultrasonic extraction process of ampelopsisgrossedentata flavonoid compounds. The resulting quadratic regression model analysis determinedthe optimal condition for the ultrasonic extraction of ampelopsis grossedentata flavonoidcompounds as follows: liquid to solid ratio29.4:1; ultrasonic temperature66.10℃, ethanolconcentration73%, ultrasonic time41min, the net percent yield was15.161%.2、Ultrasound-assisted Bionic ExtractionThe percent yield of extraction was used as the standard index, and with the consideration ofcost-effectiveness, the most suitable enzyme used to extract ampelopsis grossedentata flavonoidcompounds is determined to be cellulase at pH5.0. One-factor experimental design was utilized andthe following parameters were found to result in the highest percent yield of flavonoid compounds extracts: enzyme amount1.2%, grinding particle size60μm, extraction temperature65℃~75℃,extraction time15~25min, ultrasonic power150~210W, liquid to solid ratio100:1~120:1.On the basis of one-factor experiment, four most influential parameters (extraction time,temperature, liquid to solid ratio and ultrasonic power) were selected and analyzed using responsesurface methodology to optimize the ultrasoun-assisted bionic extraction process of ampelopsisgrossedentata flavonoid compounds. The resulting quadratic regression model analysis determinedthe optimal condition for the ultrasound-assisted bionic extraction of ampelopsis grossedentataflavonoid compounds as follows: extraction time22min, extraction temperature71.80℃, liquid tosolid ratio111.20:1, ultrasonic power180W, the net percent yield was15.728%, which is superiorto ultrasonic organic solvent extraction method.3、Measuring the proportion of flavonoids content in different solvent extracts of ampelopsisgrossedentataThe following solvent extracts were arranged from the highest proportion of flavonoids to thelowest proportion: ethanol extract> methanol extract> acetone extract> water extract> ethylacetate extract> petroleum ether extract.4、The measurement of antioxidant activity indexDifferent solvent extracts of ampelopsis grossedentata were measured and evaluated on theirantioxidant activity, their abilities to clear ABTS·+, DPPH·,·OH, and O2·-and their anti-lipidperoxidation activity. The result demonstrated that ethanol extract has the strongest antioxidantactivity (total antioxidant activity of90.23mg/mL) and highest clearance effect on DPPH·,·OH,and O2·-with IC50of7.85mg/L,17.94mg/L and13.09mg/L respectively. Ethyl acetate extract hasthe highest clearance effect on ABTS·+(TEAC=8.97mmol/g). Petroleum ether has the strongestanti-lipid peroxidation activity (IC50=141.18mg/L).5、Investigation on the possible correlation between the amount of flavonoids contents insolvent extracts and its antioxidant activityResults of the research indicates that the level of total antioxidant activity of differentampelopsis grossedentata extracts and their ability to clear DPPH·,·OH, and O2·-is proportional tothe amount of flavonoids content. With regards to the ability to clear ABTS·+and anti-lipid peroxidation activity, fat-soluble antioxidants demonstrated a relatively strong antioxidant property.Therefore, we can conclude that flavonoid has the most important role in the antioxidant activity ofampelopsis grossedentata extracts.