Study On The Separation, Identification Of Flavonoids From Chinese Bayberry Fruits And Extraction, Analysis Of Its Kernel Oil

Chinese bayberry（Myrica rubra Sieb.et Zucc） belongs to the branch of Myrica, genus of Myrica.There are plenty of bioactive substances,such as flavonoids and anthocyanin in fruits of Chinese bayberry.In this paper,the extraction,purification, identification and antioxidant activity of flavonoids from different varieties of bayberry were studied.In addition,the optimal extraction condition of oil from kernel of bayberry was established,and its fatty acid were analyzed by GC/MS.The results were as follows:The extraction technology of general refluxing extract and Ultrasonic-assisted extract were established.When the material was extracted with 70%ethanol（pH3） at 45℃for 3 h,and with the ratio of material to liquid（w/v） 1:10,the flavonoid content of extract was 2.588 mg/mL.The optimal condition of Ultrasonic-assisted extraction as that 60%ethanol（pH3） as extract solvent,extract temperature 45℃,power 300 W,time 3 min and at the ratio of material to liquid（w/v） 1:10,the flavonoid content of extract was 3.023 mg/mL under this condition.Characteristic of static,absorption and desorption about five kinds of macroporous resins for purifying flavonoids from Bayberry were studied.The results showed that AB-8 macroporous resin was the best,and its optimal separation condition were:60%ethanol（pH=3） as eluting solvent,the ratio of column diameter to height 1:10,adsorption capacity 1.889 mg/mL and eluting volume 50 mL at the speed of 1.0 mL/min.Under this condition,the flavonoids content of the extraction was 74.75%.The Polyamide and Sephadex LH-20 column were used for the futher purification of flavonoids.B and C two fractions were obtained.According to TLC and HPLC analyses,fraction B has only one component,which is Myricetin identified by UV、IR and MS.Fractions C has two components,maybe Rutin and Myricetin. HPLC-MS analysis showed that Kaempferol hexoside,Myricetin hexoside,Myricetin deoxy hexoside and Quercetin deoxyhexoside were the main flavonoids in the fruits of Chinese bayberry.The total flavonoids content in different varieties of bayberry fruits were analyzed by colorimetry and HPLC.The results showed that the flavonoids content in BIQI（2.892 mg/g） was higher than that of other varieties of bayberry such as SHUIJING1（1.093 mg/g）,SHUIJING2（1.163mg/g）,SHUIJING3（1.287mg/g）, FENHONG（0.983mg/g）.HPLC analyses showed that rutin and myricitrin content in BIQI bayberry fruits were higher,which was 1.030 mg/g and 1.320 mg/g respectively.In other varieties of bayberry,myricitrin content was much more,wheras the rutin and myricetin were lower.Different systems were used to study the anti-oxidative activities of different varieties of bayberry and their extracts.Antioxidant activity of "BIQI" bayberry fruit and its extract were higher than that of the others.The antioxidant activity was positively correlated with flavonoid content in bayberry fruit by correlation analysisA second order quadratic equation of oil in the kernel of bayberry extracted with supercritical CO₂ was established by response surface methodology（RSM）.The optimal technology is:temperature 52.20℃,time 12.6 min and pressure 35.03 MPa. Under this condition,the yield of oil was 62.35%.The fatty acid analysis by GC/MS showed that the palm acid,stearic acid,oleic acidoil,linolenic acid were the main fatty acids.And the unsaturated fatty acids content is above 80%.