The Chemical Constituents Of The Mountain Leaves

Manshanhong which was also called Dazixiang,derived from the dried leaves of Rhododendron dauricum L., has the function of relieving cough and reducing sputum which is used to cure the acute and chronic bronchitis in the clinical practice. It has also been reported that Rhododendri Daurici has the effect to cure keshan diseases.It mainly distributes in the northeast areas and has the characteristics such as rich resources,remarkable treatment effect and little side effect. In order to search for the active components and chemical constituents of Rhododendron dauricum L., a primary study was carried out in this dissertation.Manshanhong leaves which was used in this article was first identified to be the Rhododendron dauricum L. by professor Jianping Gao , Pharmaceutical School of Shanxi Medical University.Compounds No.1-14 were isolated from chloroform extraction portion and ether acetate extraction portion from Rhododendron dauricum L. by chromatography with silica gel,polyamide and Sephadex LH-20.First, 5.5 kg leaves of Rhododendron dauricum L.were refluxed with 95% ethanol for 3 times,1 hours every time. The solution was concentrated to form the extract. The extract was then mixed by water, and extracted with petroleum ether,chloroform, ether acetate and normal butanol in turns. The extracts were 250g, 80g,180g, 50g and 200g respectively.The chloroform fraction was separated by silica gel column chromatography and was eluted by different concerntration petroleum ether-ether acetate (l:0→0:l),250ml for every fraction with TLC to test the eluted solution, the same fractions was united.Eleven compounds (No.1 to 11) were obtained.Compound 1 is white columnar crystal (see table 1),compound 2,5,10 and 11 is colorless needle crystal,compound 3,4,4/,6 and 9 is white crystal,compound 7 and 8 is green needle crystal(see table 1.1).The ether acetate fraction was separated by a Polyamide (PA), dried in the air,grinded, and eluted with water, 10%, 30%, 50%, 70% and 95% ethanol, respectively.250ml for every fraction with TLC to examine the eluted solution, three compounds (compound 12 to 14) were obtained which are yellow needle crystal(see table 1.1).The structures of thirteen compounds were characterized by melting point, IR, MS, 1H, 13C and 2D-NMR.They are l-menthol,β-sitosterols,n-tricosanoicacid- tricosyltrans,n-docosanol, n-hetanecanol,olean-12-ene-3β,24-diol,3β-hydroxy-olean-12-ene,stearic acid, ursolic acid, oleanolic acid, hyperoside, reynoutrin and quercetin.Amone them,β-sitosterols,n-tricosanoicacid- tricosyltrans,n-docosanol,n-hetanecanol,olean-12-ene-3β,24-diol,3β-hydroxy-olean-12-ene, stearic acid and reynoutrin were obtained from Rhododendron dauricum L. for the first time.