Apocynum Leaves The Chemical Composition Of Study

Apocynum venetum belongs to Apocymaceae,leaves of which are considered as a traditional herbal medicine.Several isolation methods were used for a preliminary research on chemical components of Apocynum venetum in Shaanxi.Ten compounds were achieved at last and they were elucidated by the means of spectroscopy(UV,IR,MS,¹³C-NMR, ¹H-NMR,H-H-COSY etc.) assisted by comparing with standard substance.They were: tamarixetin(1),kaempferol(2),quercetin(3),quercetin-3-O-(6″-O-malonyl)-β-D-Glucose(4),kaempferol-3-O-β-D-Glucose(5),quercetin-3-O-β-D-Glucose(6), flavone(7),rutin(8),quercetin-3-O-β-D-Glc(2â†'1)-β-D-Glucose(9),β-sitosterol (10),tamarixetinis isolated from Apocynurn venetum for the first time.On the basis of having systematically isolated chemical composition of Apocynum venetum,seven flavone were determined by RP-HPLC.The seven components were kaempferol,quercetin,quercetin-3-O-(6″-O-malonyl)-β-D-Glucose,kaempferol-3-O-β-D-Glucose,quercetin-3-O-β-D-Glucose,rutin,quercetin-3-O-β-D-Glc(2â†'1)-β-D-Glucose.In reversed-phase high performance liquid chromatography,samples were determined under the condition of 362nm at 25℃..the mobile phase for separating seven components was water with 0.1%acetic acid/acetonitrile(85%/15%,by volume),followed at 13min acetonitrile was changed to 20%immediately,the mobile phase was step-changed to 60%/40%from 30min to 45min,and finally it was maintained in this conditon to the end fo the run time at 55min.This method was proved to be simple,reproducible and accurate.Through the determination of RP-HPLC,we found that quercetin-3-O-β-D-Glucose and quercetin-3-O-β-D-Glc(2â†'1)-β-D-Glucose are the main components in Apocynum venetum,their contents in Apocynum venetum is 1-3%and 2-5%respectively.Flavones is more and higher contents in Apocynum venetum of Shaanxi province and Xin Jiang province than others'habitats.Part three studied on the antioxidant activities of main components—quercetin-3-O-β-D-Glucose and quercetin-3-O-β-D-Glc(2â†'1)-β-D-Glucose in Apocynum venetum and its extract.we researched the antioxidant activities of them compared with Vc.Two standard substances showed stronger activities than Vc,can become the alternative antioxidant.At the same time,medical materials of different habitats displayed strong anti-DPPH activities, which indicated them can be further to be exploited for health care products of anti-aging.