Studies On Chemical Components And Pharmacological And Biological Activities In Huyou Peels

Citrus Changshan-huyou Y. B. Chang is a hybrid of Citrus grandis (Linn.) Osbeck and C. sinensis (Linn.) Osbeck in genus Citrus. It is widely distributed in Changshan^ Quzhou, Longyou> Jiangshan and Kaihua regions of Zhejiang province; with the greatest population being found in Changshan. The study was conducted to understand the chemical constituents from the Huyou peels. The objective was to screen the biological and pharmacological activities, develop new healthy foods and offer a chemical basis for evaluation of quality standards and pharmacological activities. It would serve as a basis for value-added development and utilization of citrus resources, as well as promote Chinese traditional medicine. The main results were as follows:The chemical constituents of Huyou peels were studied systematically. 31 compounds were isolated by repeated column chromatography and elucidated on the basis of various spectral analysis (1D-NMR, 2D-NMR, MS, IR etc.). Among the isolated compounds were 2 new compounds that have never been reported in natural products and organic synthesis. The other 29 compounds although having been isolated from other plants, were however isolated for the first time in this plant The flavanones and their glycosides-hesperidin and naringin-were the primary components粀hile polymethoxylated flavones and limonoids were the subsidiary components. P -ionone anague isolated from the Huyou peels has 13 carbons. It is rare and not abundant as a natural product in nature. It has never been reported in Citrus, and was therefore being isolated for the first time in Citrus.The ideal extracting technology for flavonoids in peels was investigated by using quad ratio rotational combination designs. The results showed that extracting of flavonoids was significantly affected by time, ratio of material to solvent, temperature and alcohol contents. Extracting time was the primary condition, while the ratio of material to solvent was the second most important condition. Extracting was affected less by extracting temperature and alcohol contents than by other conditions. Theyield increased as the temperature, alcohol content and extension of extracting time increase; but decreased as the ratio of material to solvent increases. The best extracting conditions were 90% alcohol content, a ratio of 1 '5 material to solvent, 115 minutes and 20 ℃. The maximal extraction rate of the flavonoids was above 1.98mg/ml. The industrial extracting conditions that we recommend are 80% alcohol content, a 1 '. 8 ratio of material to solvent, 100 minutes and 50 ℃. extracting time and temperature respectively.Another 49 chemical constituents of volatile oils (mostly terpenes) extracted from the Huyou peels were identified by using GC-MS-DS technique. The primary component was Limonene (relative content: 35.292%, molecular weight: 136).In vitro, that the volatile oils have a manifest antibacterial and antifungal activities had been established. Microsporum gypseum and Trichophyton rubrum are sensitive to the volatile oils. The MIC were 0.025Hl/ml and 0.00625W/ml. The results showed that some chemical constituents had good inhibitory effects for T cell and B cell proliferation reaction; making us conclude that the chloroform fraction was the immune bioactivities section. The effect of anti-cruor was not effective. Meanwhile, the study confirmed that the flavonoids extracted from the Huyou peels had the relationship of structure-effect as the scavenge reagents of free radicals. The ability of different samples scavenging O2- was 50 times that of scavenging ?OH . The flavonoids from the Huyou peels was effective scavenge reagents of free radicals.This study can not only stimulate the development of citrus processing, but also enhance the comprehensive utilization of citrus by-products. It can stimulate a new approach for the valued-added utilization and development of citrus residues.