Hesperidin Extraction And Preparation Of Its Derivatives

Hesperidin,is the most abundant flavonoids in the orange peel, has effects of lower cholesterol, prevention of cardiovascular disease, resistant to hydroxyl radical oxidation, anticancer and disinfection. Hesperidin is the basic material for preparing flavonoids drugs, natural antioxidants and food additive. The main work of this paper is to study extraction and purification of hesperidin, synthesis of hesperidin derivatives and synthesis of new fluorine hesperidin derivatives.The main content of this article was divided into three parts:First,the technology condition of extracting hesperidin from orange peel was determined through the research of extraction solvent, solvents and orange peel powder material to liquid ratio, extracting time, extracting pH value, temperature, etc for single factor experiment, orthogonal experiment was also carried out to pick up optimum condition of technology. Recrystallation which is handled easily was used in the purification. DMF is the best solvent for recrystallation, and at the same time, the best process was optimized here. The purified hesperidin was hoar, reached 98% purity and yield of 3%.Secondly, with the reaction of hydrolyzation, demethylation, dehydrogenation, and synthesis condition, hesperedin was used to prepare hesperetin, eriodictyol, persicogenin, diosmin and dios-metin which have potential medicinal values of flavonoids, and the reaction conditions were in-depth study at the same time.Various reaction system for synthing hesperetin was tested in this article , the most suitable system is ethanol/sulfuric acid, the system of acetone/water was used in the purification and gets hesperetin with 99.1%(HPLC) purity and 91% yield; The reaction conditions of dimethyl carbonate substituted for dimethyl sulfate for O-alkylation reaction was researched in synthesis of persicogenin , but experimental results shows dimethyl carbonate can't successful substitute dimethyl sulfate; The temperature when feeding AlCl3 and reaction temperature was researched in synthesis of eriodictyol to control the produce of pyridine hydrochloride and improve product purity; Ddiosmin was synthesized by dehydrogenation with I2 / pyridine system, and the reaction temperature and time was also optimized, the reaction time should be more than 10h and the temperature should be beyond 95℃. Dios-metin and hesperetin were prepared with same method, ethanol/sulfuric acid system was chosen finally.At last, 7-(2, 2, 2-trifluoroethox) hesperetin was synthesized in this paper, which is start from Hesperitin and 2, 2, 2–trifluoroethyl iodide and TsOCH2CF3 for O-alkylation reagents. This compound is new flavonoids for the first time reported, and structure of the compound have been confirmed by MS, IR, ¹H NMR and ¹³C NMR .