Study On Antioxidative Components Of Iris.halophila Pall.Root

The relations of oxidation and disease, food rot were reviewed, researches on natural anti-oxidative products and chemical compounds from Iris L.and Iris.halophila Pall. were also summarized in this thesis.The predictive-analysis test showed that the main components in 95% ethanol extract are flavones,phenolic compounds,amylose,organic acid。The 95% ethanol extract of I.halophila Pall. root was divided into ethyl-acetate fraction, n-butanol fraction, aqueous fraction and petroleum-ether fraction, the anti-oxidative activities of different fractions except petroleum-ether fraction were analyzed by DPPH means and estimated by EC₅₀ and AE parameters which were compared with BHT's, UV absorption spectrum was also used to analyze the main components in these fractions. As a result, three fractions all have DPPH radical scavenging activity, the order of EC₅₀ is BHT>n-butanol fraction>aqueous fraction> ethyl-acetate fraction, meanwhile the order of AE is n-butanol fraction >BHT> aqueous fraction > ethyl-acetate fraction, it was indicated that n-butanol fraction has better antiradical efficiencies(AE) than BHT's, the UV absorption spectrum indicated that the main components in every fraction are iso-flavones.Four compounds were isolated from ethyl-acetate fraction by using chromatography technology, and they are first isolated from I.halophila Pall., the structures of the four compounds were identified by using UV,IR,MS,NMR and X-ray diffraction technologies. The four compounds are 6,4'-dimethoxy-5,7-dihydr-oxy-isoflavone;5,7,3'-trihydroxy-6,7,4'-trimethoxy-isoflavone(Irigenin);5,4'dihydroxy-6,7–methylenedioxy-isoflavone(Irilone) and 5-Methoxy-4'-hydroxy-6,7-methy-lenedioxy-iso-flavone(Nigrigin).Nigri- gin was characteri-zed by single-crystal X-ray diffraction, bond lengths and bond angle of Nigrigin molecular were studied by X-ray diffraction. The detail document of Nigrigin molecular was registered in Cambridge Crystallograp- hic Data Centre(CCDC), the registered number is: 645846.Anti-oxidative activity of the four compounds were analyzed by DPPH means, the result is that the activity of 5,4'-dihydroxy-6,7-methyllenedioxy- isoflavone is better than other three compounds, but lower than BHT's.