Study On Chemical Constituents And Antioxidant Activity Of Chinese Medicinal Herb Youngia Jiaponica

Youngia japonica is the plant of Youngia Cass of Lactucinae Less. of Compositae, be distributed our country chiefly, have a world of exploitation potentiality. Research indicateds that Youngia japonica contains Terpene and Phenols, have curative effect in anti-virus and anticancer. The article adopts sichuan Youngia japonica, and study chemical composition adopting color spectrum, and analysis single compound adopting IR and NMR spectrum an so on. To determin the antioxidative activity adopts vitro- antioxidative methods and apigenin and β-daucosterol contents adopting HPLC methods.The article separates 8 compounds to use the stratography, and adopt physics and chemistry and spectrum methods to identify 7 compounds. taraxasteryl acetate (I), n-docosanol(II). β-sitosterol and stigmasterol (III) , retinol (IV). β-daucosterol (V), docosanoic acid (VI), apigeniri(VIII)All compounds are found in this plant for the first time.The spectrophotometric method were used to determine the protective effects on damage of spontaneously lipid peroxidation in homogenates of rat heart, liver, and kidneys. Its protective effects on damage and lipid peroxidation of liver and red blood cell induced by H₂O₂. Its eliminating effect of hydroxyl radical(? OH). Results indicate that the extracts from Youngia japonica. exhibited a significant potency inhibiting in spontaneously lipid peroxidation in rat heart, liver, and kidneys. Its inhibiting in rat liver homogenate and erythrocyte hemolysis induced by H₂O₂. The hydroxyl free radical induced by Fenton reaction could be scavenged effectively. The antioxidant activity of Youngia japonica' s ethyl acetate parts is fairly powerful, and determin the antioxidant activity of the apigenin, and find the apignin has the effective antioxidant activity, so the apignin is one of the biological activity components possibility.To determine its content in Youngia japonica by HPLC method , The chromatographic condition determining apigenin included: mobilphase consisting of a mixture of methanol-0.4% phosphonic acid (65 : 35) , and flow rate of 0.80mL.min^-1 ,and detection wavelength of 360nm , and a column temperature of 30°C, and recovery rate is 99.05%(RSD=2.0 %), the calibration was linear in the range of 28.80 144.00 μ g.mL^-1, the average contents of apigenin is 0.00739%. The chromatographic condition determining β-daucosterol included: mobilphase consisting of a mixture of water-methyl cyanide (65:35) , and flow rate of l.0mL.min^-1, and detection wavelength of 203nm , and a column temperature of 30°C, and recovery rate is 99.28%(RSD= 1.51 %), the calibration was linear in the range of 3.84～15.36μ g.mL^-1, the average contents of β- daucosterol is 0.434 %. The HPLC method is accurate, fast and repeatable for the determination.