Study On Extraction Of Isoflavone Glucosides From Sophora Japonica Pod By Homogenate Ultrasonic-Synergistic Extraction And Catalytic Conversion For The Preparation Of Genistein

Sophora japonica pod is the pod of Sophora japonicum(L.)Schott,a tree in the legume family,which is used as a medicine after concoction when mature.Sophora japonicum is grown in most provinces and regions of China and is widely distributed.Research on chemical composition shows that Sophora japonicum pod is rich in isoflavones,mainly genistin and sophoricoside,which are considered as phytoestrogens and have the effect of preventing osteoporosis and cardiovascular lesions and anti-cancer.In order to make full use of the resources of Sophora japonica pod,an efficient and green homogenization ultrasonic synergistic extraction method was established to extract the genistin and sophoricoside from Sophora japonica pod,and the extraction process was optimized by single-factor experiment and Doehlert design combined with desirability function.Then,the extracted genistin and sophoricoside were converted into genistein that can be better absorbed and utilized by human body under the condition of microwave irradiation using 001×7 strong acidic cation exchange resin as a solid acid catalyst,and the conversion process was optimized by single-factor experiment and Box-Behnken optimization method to determine the optimal conversion conditions.The main elements are as follows:1.The extraction of genistin and sophoricoside was carried out by homogenization ultrasonic-synergistic extraction method with ethanol solution as the extraction solvent and high performance liquid chromatography as the quantitative means.Under the extraction conditions of 60% ethanol concentration,25 m L/g liquid-to-solid ratio,3 min homogenization time,22000 r/min homogenization rate,35 min ultrasonic irradiation time,350 W ultrasonic irradiation power,2.5 s ultrasonic cavitation time and 1.5 s ultrasonic interval time,the highest yields of genistin and sophoricoside were obtained,which were 34.6 ± 0.1 and 98.8 ± 0.1 mg/g,respectively.It provides a new idea for the improvement of the extraction method of genistin and sophoricoside in Sophora japonica pod.2.Using a solid acid cation exchange resin as a catalyst,the extracted genistin and sophoricoside were hydrolyzed and converted into genistein that can be better absorbed and utilized by human body under the condition of microwave irradiation.After the experiment,001×7 cation exchange resin was selected as the catalyst from five resins,NKC-9,HZ008,D001-CC,001×7 and 732,and 0.5 g of crude extract of isoflavones was dissolved with 50 m L of n-butanol,and the conversion experiment was conducted under microwave irradiation conditions with the conversion rate of dye lignin as the measurement index.The conversion parameters were optimized by single-factor experiment and response surface optimization method,and the optimum conversion process was finally determined as 115 min microwave irradiation time,642.5 W microwave irradiation power,12.9 m L/g liquid-solid ratio of n-butanol to resin,and the conversion rate of genistein could reach 94.1% under this condition.In this study,the homogenization ultrasonic-synergistic extraction method was used to simultaneously extract the genistin and sophoricoside from Sophora japonica pod,and the extraction process was optimized by using Doehlert design and desirability function,and the experimental results proved that the extraction process was fast and efficient,excellent and stable;After that,we tried to hydrolyze the genistin and sophoroside by using cation exchange resin under the condition of microwave heating to produce genistein.The method is simple,with high conversion rate and meets the production standard of green chemistry.