Studies On The Extraction And Transform Technology And The Antioxidation Activity Of Flavonols From Myrica Rubra Leaves

Myrica rubra(Lour.)Zucc.is Myricaceae Myrica linn.plants,and has High nutritional value.Main producing areas is Zhejiang and Fujian,they Myrica rubra planting and processing has gradually become a characteristic industry of rural economy.Myrica rubra leaves commonly used as traditional Chinese medicine,in mainland China,Taiwan and Japan are often used to detoxification and antidiarrheal,etc.Early research has shown that Myrica rubra leaves rich in flavonols such as Myricetin,Quercetin and kaempferol which are rich in bioactive.This paper with myrica rubra leaves as the research object,studied the extraction and conversion of acid solution process of flavonol form Myrica rubra leaves,in order to provide theoretical evidence for the research and development of myrica rubra leaf.(1)Established the simultaneous determination of Myricetin,Quercetin and kaempferol by RP-HPLC method for quantitative analysis,chromatographic conditions:Waters XB-C18 chromatographic column(250 mm x 4.6 mm,5 microns);Mobile phase:Acetonitrile:0.07%Trifluoroacetic acid aqueous solution:0.07%Phosphoric acid solution for 30:35:35;Column temperature 25 ℃.The flow rate of 0.8 ml/min;detection wavelength of 370 nm.(2)The process of Myricetin,Quercetin and kaempferol form myrica rubra leaves by the ultrasonic assisted extraction was studied in this experiment.The experimental results show that the best parameters of the ultrasonic assisted methanol extraction were as follows:The extraction temperature is 70 ℃,the crushing size is 60 item,the methanol concentration is 78%,the solid-liquid ratio is 1:38,the extraction time is 31 min and the ultrasonic power is 450 w,And at the optimum conditions,the extraction rate of three substances is 78.4 mu g/g.(3)On the basis of the optimal extraction technology,using ultrasonic assisted acidolysis myrica rubra leaves extract for preparation of three kinds of flavonols,concluded that the best process parameters for:70 ℃,HCl 8 ml which concentration is 10 M/L,time of 45 min,power 450 w.Under this condition,1 g myrica rubra leaves can be extracted into 7.93 mg of Myricetin,Quercetin and kaempferol.(4)The same concentration(2 mg/mL)extract,acidolysis products compare to ascorbic acid solution of total antioxidant capacity,the results showed that total antioxidant capacity of both two types are weaker than ascorbic acid,and its total antioxidant capacity sort:ascorbic acid>acid>extract solution products.IC50 results show that:the concentration range from 0.1 mg/mL to 1.0 mg/mL,the ability of scavenging free radicals ability of sample order is:ascorbic acid>acid>extract solution products;At 0.2 mg/mL-3.0 mg/mL concentration range,the ability of resist lipid peroxidation of sample order is:ascorbic acid>acid>extract solution products.