Study On Extraction And Purification Of Ginkgo Biloba Leaf Flavonoids

Ginkgo biloba is a deciduous tree of Ginkgo biloba families and Ginkgo biloba genera.It is one of the long-standing Chinese herbal medicines in China.Medicinal value of Ginkgo biloba leaves prominent.The traditional method efficiency low,which is important reasons for its limited application.This project is dedicated to the development and utilization of flavonoids,using ionic liquid assist in the extraction of flavonoids by microwave-ultrasonic extraction,and then exploring the extraction mechanism and purification process.In addition,it explores its oxidation resistance and stability,laying the foundation for practical application.The main findings are as follows:Using microwave-ultrasonic combined extraction method to extract flavonoids from Ginkgo leaves,based on single factor experiment,using response surface method to optimized process:ultrasonic time 4.0 min,ultrasonic power 228.0 W,microwave time 4.0 min.The ratio of liquid to liquid is 20:1 mL/g,the extraction amount of GBLF reached 24.31 mg/g.Based on the microwave-ultrasonic combined extraction method,the ionic liquid is screened.Based on the single factor experiment,using response surface method to optimize the extraction conditions.The traditionalionicliquid1-butyl-3methylimidazoliumphosphate dihydrogen salt optimized process:concentraction 0.75 mol/L,ultrasonic power 66.0 W,ultrasonic time 6.0 min,microwave time 2.0 min.The extraction amount were 49.91 mg/g.The new ionic liquid1-butyl-3methylimidazolium glutamate optimized process:concentraction0.75 mol/L,the ultrasonic power 69.0 W,ultrasound time 6.5 min,microwave time 2.0 min,the extraction amount were 41.42 mg/g.Explain the reasons for the increase of extraction amount from the three aspects of solubility,leaf surface morphology and intermolecular force.Purify and dry the crude ginkgo leaf flavonoids by macroporous resin and spray drying method.The macroporous resin HPD-100 is used to purify the crude flavonoids,When loading concentration 0.75 mg/mL,loading flow rate 0.5 BV/h,loading volume 160 mL,and the eluent60%ethanol.The aqueous solution,the sample solution pH=6,the elution flow rate of 2.0 BV/h,the elution volume of 55 mL.The crude flavonoids could be upgrad from the purity of 24.00%to 74.12%.Subsequently,the flavonoid product is dried by spray drying.When feed rate 9 mL/min,the feed concentration 40 mg/mL,the fan frequency 50 Hz,and the inlet temperature 180℃,the product purity was up to 81.24%.The structure of the extract was consistent with the flavonoid structure.Considering the subsequent development of the product,the research on the oxidation resistance and stability of flavonoids in Ginkgo biloba leaves is carried out.The experimental results show that the product had good anti-oxidation effect,and should avoid illumination,excessive temperature,peracid and alkali,contacted with Na₂SO₃,Fe²⁺,Fe³⁺and excessive concentration of Vitamin C and citric acid during production and storage.Through the above work,the process of ionic liquid assisted microwave-ultrasonic extraction of flavonoids from Ginkgo biloba leaves and its extraction mechanism were obtained.Secondly,the macroporous resin purification process and the spray drying process were obtained a product with purity of 81.24%.In addition,explore its antioxidant properties and stability.The innovation of this subject lies in the extraction of flavonoids from Ginkgo biloba leaves by ionic liquid and microwave-ultrasonic extraction method.Extraction time is obviously shortened,and the product purity is higher.The developed process is convenient and reliable,and provides strong support for the development of flavonoids in Ginkgo biloba.