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Preparation of flavonoids from Osmanthus dregs and enzymatic modification(PDF)

Journal of Forestry Engineering[ISSN:2096-1359/CN:32-1862/S]

2020 No.06
Research Field:
林产化学加工 执行主编:王飞 张美云
Publishing date:


Preparation of flavonoids from Osmanthus dregs and enzymatic modification
FANG Xianying1 ZHOU Jianglian1 WANG Jingqiu1 TANG Feng2 ZHAO Linguo1*
1. College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China; 2. International Center for Bamboo and Rattan, Beijing 100102, China
flavonoids Osmanthus dregs biocatalysis enzymatic modification bioactivity
Osmanthus fragrans is a traditional famous flower, which is usually used for Ornamental plant, food, essential oil production and some other fields. The essential oil of O. fragrans is widely appreciated by consumers due to its advantages of pleasure smell, relieving fatigue, analgesia, soothing mood and maintaining beauty function. Because of the low extraction yield and high price of essential oil, it would be a great waste of O. fragrans resources if the Osmanthus dregs (the essential oil extraction residue from O. fragrans) are discarded. Previous studies have shown that there are many nonvolatile components, such as flavonoids, in O. fragrans, which have a wide range of biological activities. In this paper, the efficient utilization of Osmanthus dregs, the biocatalysis of the total flavonoids from O. fragrans and the changes of the components and biological activities before and after the biocatalysis of Osmanthus flavonoids were studied. The contents of total flavonoids in the petals of four O. fragrans were compared and the ‘Jingui’ was selected as a raw material. It was found that O. fragrans is rich in flavonoids, the content of which is up to 42.6% in ‘Jingui’ petals, and most of them remain in the dregs. The content of flavonoids in Osmanthus dregs was up to 38.7% determined by the rutin method, which indicated that the dregs of O. fragrans had high utilization value and development prospect. Natural flavonoids mostly exist in the form of glycosides, so are the flavonoids from O. fragrans. Studies have shown that the reduction in the amount of Oglycosylation can improve the antioxidation, antidiabetic, antiinflammatory, antibacterial and antitumor activities of flavonoids. The major glycosides in Osmanthus flavonoids are glucoside and a small amount of rhamnoside. On this basis, the effects of enzymatic catalysis of Osmanthus flavonoids on its components and activities were studied. Results showed that part of the flavonoid glycosides in O. fragrans can be hydrolyzed to flavonoids with less glycosyl number or flavonoid aglycone by βglucosidase and αLrhamnosidase. There were more glucosyl groups in the terminal or secondary terminal of the Osmanthus flavonoid glycosides, but little rhamnosyl. The antiinflammatory, antioxidation and antitumor activities of the samples transformed by βglucosidase were significantly higher than that of the samples being not transformed by βglucosidase. The inhibition rate on the proliferation of human hepatoma HepG2 cells of Osmanthus flavonoids transformed by βglucosidase was up to 85%, the IC50 value was 51.32 μg/mL, and the mechanism of which was promoting the apoptosis of tumor cells. The research data can provide a new idea for the comprehensive and efficient utilization of Osmanthus resources and provide technical support for the preparation of Osmanthus flavonoids with higher biological activities.



Last Update: 2020-11-11