Chemical Constituents From The Fruits Of Wild Species Of Crataegus Scabrifolia And Their Lipid-Lowering Activities

This dissertation is composed of two chapter during the period of master’s degree.Chapter one mainly expounded the investigation on the chemical constituents of the fruits of wild species of Crataegus scabrifolia(Franch.)Rehd.and their lipid-lowering activities in vitro,and determination of the principal constituents of C.scabrifolia.Chapter two primarily described the research progress on plant origin and pharmacological activity of phlorizin.Objective: To study the chemical constituents of the fruits of wild species of C.scabrifolia and their lipid-lowering activities.Methods: The compounds were isolated and purified by various column chromatography padded with silica gel and Sephadex LH-20,respectively,and their structures were identified based on the comprehensive analyses of the physicochemical properties and spectral data.The lipid-lowering activity in vitro was evaluated by cellular model of Hep G2.Results: Twenty-six compounds were obtained from the 95% ethanol extract of the fruits of wild species of C.scabrifolia and identified as β-amyrin(1),α-amyrin(2),oleanolic acid(3),ursolic acid(4),pomolic acid(5),tormentic acid(6),2α,19α-dihydroxy-3-oxo-urs-12-en-28-oic acid(7),euscaphic acid(8),fupanzic acid(9),3-epifriedelinol(10),quercetin(11),quercetin-3-O-glucoside(12),helicioside B(13),phloretin(14),phlorizin(15),3-hydroxyl-phlorizin(16),phloretin-2’-xyloglucoside(17),crataeoside A(18),alphitonin 4-O-β-D-glucoside(19),aureusidin-6-O-β-Dglucopyranoside(20),β-sitosterol(21),daucosterol(22),benzoic acid(23),2-hydroxybutanedioic acid dimethylester(24),2-hydroxy-butanedioic acid 1-methylester(25)and palmitic acid(26).Compounds 7,8,11,14 and 15 showed a lipid-lowering rate of9.02 ± 12.01%,5.56 ± 2.74%,12.84 ± 10.25%,4.76 ± 12.23% and 9.64 ± 6.26%.at the dose of 200 μM.Compounds 1-4,6,9,10,12,13 and 16-26 showed no significant lipid reduction at 200 μM.Compounds 15 and 17 are the major constituents of the C.scabrifolia with the contents of 0.193% and 0.115%,respectively.Conclusion: Terpenoids and flavonoids are the major constituents of the C.scabrifolia.Compound 18 from the C.scabrifolia was identified as a new compound.Compounds 1,2,5,7,9,10,13,14,15,17,19,24 and 25 were isolated from the plants of Crataegus for the first time,and compounds 3,6,8,12,15,20,23 and 26 were isolated from the C.scabrifolia for the first time.Compounds 7,8,11,14 and 15 showed undoubted lipid-lowering activity in vitro.Compounds 1-4,6,9,10,12,13 and 16-26 had no lipid lowering activity in vitro.Compounds 15 and 16 are the major constituents of the C.scabrifolia.