Study Of The Polymethoxylated Flavonoids In Fructus Aurantii Immaturus

There are so many papers about the medical and pharmaceutical of the flavones in Citrus. Hesperidin has a relationship with the vascular permeability and capillary embrittlement to a large extent. In recent years, attention has shifted to polymethoxylated flavonoids, because such components have potential anticancer activity.Fructus aurantii immaturus is the dry fruits of the Citrus aurantium L and Citrus sinensis OsbeckRutaceae. This plant is used to treat indigestion and cough, and it is also used to treat dilatation, bathygastriastomach, metroptosis, prolapse and so on. In recent years, there are more and more reports of anti-cancer activity of polymethoxylated flavonoids constituents in Fructus aurantii immaturus both domestic and abroad. These reports reveal that the polymethoxylated flavonoids have the potential anticancer effect. So we did a in-depth study of the polymethoxylated flavonoids, this paper is divided into six parts.Firstly, documents about the research progresses in chemical constituents and pharmacological activities of polymethoxylated flavonoids in Citrus plants in last twenty years were summed up and analyzed, 41 references were cited. The first part focuses on the research progress of the chemical components of the citrus plant, the report of polymethoxylated flavonoid is the main content in this part. Second part focuses on the pharmacological activity of polymethoxylated flavonoids, anticancer activity of polymet hoxylated flavonoids is the main content of this part. Through this review, we get a better understanding of polymethoxylated flavonoids.In the second part, we did a research of the polymethoxylated flavonoids in Fructus aurantii immaturus, seven compounds were isolated from Fructus aurantii immaturus through column chromatography, Five of them are polymethoxylated flavonoids. They are 5-O-Desmethyl nobiletin (compound 1), Ponkanetin (compound 2), Nobiletin(compound 3), Sinensetin(compound 4), 5,7,8,4'-tetramethoxyflavone(compound 5), Hesperidin (compound 6), Methyl Hesperidine(compound 7). Compound 7 was isolated from this plant for the first time.The third part of this paper was to establish methods of determining the polymethoxylated flavonoids in the Fructus aurantii immaturus. The contents of index compounds including 5-O-Desmethyl nobiletin, Ponkanetin and Sinensetin are determined by HPLC. The calibration curves of 5-O-Desmethyl nobiletin, Ponkanetin and Sinensetin were in good linearity over the range of 0.128～0.384μg, 0.0984～0.2952μg and 0.0912～0.2736μg, with r=0.9999, 0.9999 and 0.9999, respectively. The average recoveries for 5-O-Desmethyl nobiletin, Ponkanetin and Sinensetin were 100.2%, and 99.74%, and 100.3% with RSD(n=5) were 0.11%, and with RSD(n=5) were 0.19%, and with RSD(n=5) were 0.28%, respectively.The ratio of these three polymethoxylated flavonoids is 1:5:3. We conclude an equation by measuring the RF of Ponkanetin, through this equation we can get the total content of these three polymethoxylated flavonoids, by measuring the RF of Ponkanetin.The fourth part of this paper was to synthesis a serial of polymethoxylated flavonoids. We synthesis three polymethoxylated flavonoids and a polymethoxylated chalcone through rutin, hesperidin and dimethyl carbonate. These four compounds were identified as 6'-hydroxy-3,4,2',4'-tetramethoxychalcone (compound 8), 3,5-dihydroxy-7,3',4'-trimethoxyflavone(compound 9), 5-hydroxy-3,7,3',4'-tetramethoxyflavone(compound 10), 3,5,7,3',4'-pentamethoxyflavone (compound 11).The growth of tumor must rely on persistent and widespread of angiogenesis, recent studies show that the beginning and transfer of tumor is so closely relate with tumor angiogenesis, so inhibit the formation and growth of tumor angiogenesis is a new direction to inhibit the tumor. The activity of anti-angiogenesis was determined by quantitation of vessels on chick embryo chorioallantoic membrane(CAM). From the analysis of experimental results, 3,5-dihydroxy-7',3',4'- trimethoxy flavone, 5-O-desmethyl nobiletin, nobiletin, 5,7,8,4'-tetramethoxyflavone play a role in inhibiting angiogenesis. Sinensetin, 3,5,7,3',4'-pentamethoxyflavone, 6'-hydroxy-3,4,2',4'-tetramethoxychalcone,5-hydroxy-3,7,3',4'-tetramethoxyflavone are unable to inhibit vascular growth. Based on the structure features of the above nine compounds, we can conclude that the compounds with the eight-methoxy are better than the ot hers in inhibiting vascular growth.Finally, the results of this experiment are summarized and discussed, according to the experimental results. We have completed the following tasks, seven compound were isolated and identified, methyl hesperidin was isolated from this plant for the first time. Establish methods of determining the polymethoxylated flavonoids in the Fructus aurantii immaturus. We synthesized three polymethoxylated flavonoids and a polymethoxylated chalcone. Seven compounds'activity of anti-angiogenesis was determined by quantitation of vessels on chick embryo chorioallantoic membrane (CAM).