Studies On Chemical Comstituents Of Clematis Akebioides

Clematis akebioides,belonging to the genus of Clematis(Ranunculaceae),is widely distributed in the tropical,subtropical in the world.It was mainly distributed in Xizang,Yunnan,Qinghai,Sichuan and Gansu province in our country.As a kind of commonly used herbal medicine,C.akebioides is used for a long history.According to the records of "Tibetan herbal medicine",aboveground parts of C.akebioides can cure "Bacon" disease,and has a good effect on chronic gastritis,abdominal lump,acute appendicitis,anthrax,long break not healing sore and so on.In order to study the distribution of chemical constituents and the basis of active substance of C.akebioides,the ethanol extracts of Clematis akebioides was investigated by silica gel column chromatography and high-speed counter-current chromatography.19 compounds were isolated from the ethanol extracts of C.akebioides by using repeat silica gel,Sephadex LH-20,MCI.The structures of 19 compounds were identified on the basis of their physical and chemical properties and techniques of modern spectroscopy.The 19 compounds were:?-sitosterol(Gl),173-ethoxyphaeophytin b(G2),quercetin(G3),caffeic acid(G4),kaempferol(G5),labd-13(E)-ene-8a,15-diol(G6),enodicytol(G7),7,3',4'-trihydroxyisoflavone(G8),isoferulic(G9),7,4'-dihydroxylflavone(G10),4,4'-dihydroxy-a-truxillic acid(G11),succinic acid(G12),isoscopoletin(G13),scopoletin(G14),scoparone(G15),?-daucosterol(G16),Ent-16?,17-dihydroxy-kauran-19-oic acid(G17),rutin(G18)and 5-hydroxymethyl-2-furaldehyde(G19).In this study,high speed countercurrent chromatography(HSCCC)was also used to separate the chemical constituents which were difficult to be separated by conventional column chromatography.9 compounds were isolated from the EC-2 and EC-4 fractions of ethyl acetate extraction by optimizing the solvent system,the flow rate and the main engine speed.7 compounds with similar structure and polarity were obtained except two compounds which have been separated by the conventional method.According to their physical and chemical properties,combined with NMR,MS and other means,the 7 compounds were elucidated as:protocatechuic acid(G20),protocatechualdehyde(G21),3,4-dihydroxyacetophenone(G22),hydroxybenzoi acid(G23),vanillic acid(G24),trans-p-coumaric acid(G25)and ferulic acid(G26).26 compounds were isolated from the ethanol extracts of C.akebioides by column chromatography and HSCCC,and these compounds belong to terpenoids,flavonoids,steroids,organic acids,coumarins,etc.Among these compounds,24 compounds(except G1 and G16)were firstly found from the ethanol extracts of this plant,and compound G2,G6,G11,G17 were firstly found from the genus of Clematis.The study results enriched the research field of natural medicinal chemistry and laid a theoretical foundation for further research and development of C.akebioides.The application of HSCCC provided a fast,economical and effective method for the separation of active components from natural products.