Study On The Flavonoid Constituents Of Salix Raddeana Laksch Of Changbai Mountain And Stimulating Fat Metabolism Activities

Salix raddeana Laksch belongs to Salix family and is used as antibecterium and diminishing inflammation herbal medicine in the local area and especially useful in curing stamotitise .It distributes in the area of Changbai mountain and Xiaoxingan mountain of northeast China. In the course of chemotaxonomic studies, a number of flavoniod glycosides have been isolated from Salix species which have been classified as flavone, flavonol,flavan-3-ol, flavavone and flavanonol etc.. The methods were carried out such as organic solvents saturate and extract, system solvents extract, column chromatography, high performance liquid chromatography, paper chromatography and thin liquid chromatography.As part of our continuing investigation on the flavonoid constituents of Salix species, we have examined the leaves of Salix malsudana Koidz and Salix babylonica.L In the research we aimed mainly to study the constituents of flavones of the leaves of Salix raddeana Laksch. Some chromatography measurements such as polyamide column chromatography and high performance liquid chromatography (HPLC ) etc and agent system method were carried out respectively to extract and isolate the constituents. From the leaves of Salix raddeana Laksch 12 flavoniods were isolated and their structures were elucidated by UV, IR, ESI-MS, 1H-NMR , 13C-NMR spectral analysis and physical-chemical properties. Two new flavone glycosides m.f.C27H30O15,m.p.243-245℃. [M]+594(ESIMS) were isolated in the n-BuOH fraction from the leaves of salix raddeana lakcsh together with seven known flavonol gliycosides. The new compounds (1,2) were characterized as two new flavonol glycosides 5, 3'-dihydroxy-4'-methoxy flavone-7-O-β -D-glucopyranosyl-(6-1)-O-a-L-arabinopyranoside (1), 5, 3'-dihydroxy-4'-methoxy flavone-7-O- β-D-glucopyranosyl-(6-1)-O-β-D-xylopyranoside(2), other seven known flavones as luteolin7-O-a-L-arabinopyranosyl(l-6) β-D-glucopyranoside(3), luteolin 7-O-β-D-xylopyranosyl(1-6) β-D- glucopyranoside (4), kaempferol -3-O-rutinoside (5), kaempferol -3-O-glucoside (6), quercetin -3-O-glucoside (7), kaempferol-3-O-galactoside (8) and quercetin-3-O-rutinoside (9). All these compounds were isolated from the plant for the first time and compound 1 and 2 were two new flavonol glycosides, compound 3 and 4 were first isolated from Salix family.The effect of the leaves of Salix raddeana Laksch on stimulating fat metabolism was studied in this essay. It is showed that the extract of alcohol anddiet-induced obese mice and influenced the small intestinal fatty acid absorption. Furthermore the extract of alcohol and n-BuOH fraction markedly decreased bloodplasma triglyceride (TG) concentration (p<0.05).Feeding a high-fat diet containing 2% and 5% Salix raddeana Laksch leaves extract reduced the increase in body weight and final parametrial adipose tissue, and the accumulation of liver triglyceride as compared to high-fat diet-fed group. Among the different solvents fractions, the n-BuOH fraction had markedly activity of stimulating fat metabolism, which implied the n-BuOH fraction containing the active constituents. In the activity measurements of compound 1,2 and 7,compound 1 and 2 significantly enhanced noradrenaline-induced lipolysis. These results demonstrated that the anti-obesity effects of Salix raddeana Laksch leaves in high-fat diet-treated mice might be due partly to the enhancing effect of compounds 1 and 2 isolated from Salix raddeana Laksch leaves on noradrenaline-induced lipolysis in adipose tissue,and to the inhibitory action of some other substance in Salix raddeana Laksch leaves. All solvents extract and fractions were not found to enhance on hormone-sensitive lipase(HSL).The results suggest that Salix raddeana Laksch leaves extract and the compounds may be developed to be an effective drug for the treatment of obesity and fatty liver caused by a high-fat diet.HPLC method was established for determination of 5, 3'-dihydroxy-4'-methoxy flavone-7-O-β-D-glucopyranosyl (6-1) O-a-L- arabinopyranoside in the sample...