Optimization,Purification,Antioxidant Activity And Component Identification Of Flavonoids From Maize Silk

In the conventional maize consumption process,people often pay more attention to the value of corn seed,and the traditional Chinese herbal corn silk that is recorded in the book is often abandoned.In recent years,with the in-depth study on the chemical composition and pharmacological effects of corn silk and the diversification of people's needs,the medicinal effect of corn silk has been paid more and more attention,and it is often developed into medicines and health products.Its application is very extensive.Flavonoids are one of the main chemical constituents of maize filaments.Systematically study the content and purification methods of flavonoids in the silk of maize hybrids,and explore their functions and structure,could not only be used to improve maize hybrid product added value and enlarge the range of its products to provide the reference,but also provide a new reference direction for corn quality breeding.Therefore,in this study,the filaments of 9 maize hybrids were used as the research object to analyze the total flavonoids content,total flavonoids antioxidant capacity,the antioxidant capacity of purified flavonoids and the structure of flavonoids.Additionally,exploring the optimal concentration of total flavonoids from the 9 corn varieties,which were purified with ethanol.The main findings are as follows:1.The total flavonoids in filaments of nine maize varieties were extracted by ultrasonic-dual enzyme method and the differences in content were compared.The results showed that there was a real difference between the total flavonoid content of 9 varieties of corn silk,and the content of Ruiyu 16 was the highest,reaching 22.65mg/g;the contents of Zhenghong 115,Zhenghong 211 and Zhenghong 311 were relatively high,and the content was between 10.29 mg/g and 14.72 mg/g;the content of Zhenghong 505 is 3.74 mg/g.2.The total reducing power of 9 varieties of filament flavonoids was consistent with the level of their flavonoid contents.The highest was Ruiyu 16,and the lowest was Zhenghong 505.Except Zhenghong 6 and Zhenghong 211,there were significant differences among other varieties.The highest flavonoids scavenging DPPH and inhibiting-OHradical were respectively Zhenghong 532 and Ruiyu 16,and the lowest ones were Zhenghong 211 and Zhenghong 2.3.The flavonoids purified from the 9 cultivars with the best elution concentration had higher DPPH free radical scavenging activity than the total flavonoids.The flavonoids purified at different concentration gradients had higher-OHradical inhibition ability than the total flavonoids,and the difference was extremely significant indicating that the purification effect is significant.After purification,Zhenghong 532 has the strongest ability to remove DPPH and inhibit-OHfree radicals.The antioxidant ability of Zhenghong 102 and Zhenghong 211 after purification is weak in 9 varieties.4.According to the antioxidant capacity of purified flavonoids,it can be judged that the best elution concentrations of ethanol used for the purification of flavonoids are as follows: Zhenghong 2 is 40%,Zhenghong 102,Zhenghong 115,Zhenghong 211 and Ruiyu 16 are 60%,Zhenghong 6,Zhenghong 311,and Zhenghong 532 are 80%,and 60% or 80% of Zhenghong 505 are both acceptable.5.HPLC chromatograms of the purified flavonoids tested by the high-performance liquid chromatography were compared with HPLC chromatograms of standard.The results show that: The samples containing rutin were identified as Zhenghong 2,Zhenghong 102,and Ruiyu 16.There is Ruiyu 16,which contains luteolin,and Zhenghong 2 and Zhenghong 311,which contain naringenin.The Zhenghong 311 contained kaempferol,and the Zhenghong 311,the Zhenghong 505,and the Zhenghong 532 contained formononetin.The five standards were not found in the remaining three species.