Studies On The Chemical Composition,Content Determination And Anrtioxidant Activity Of Orobanche Aegyptiaca Pers.

Orobanche aegyptiaca.Pers is a parasitic plant which distributed in the field or in the garden of 140-1400 meters above sea level,and it is growing in northern Africa,the eastern Mediterranean area,Arabia Peninsula,Iran,Pakistan,Crimea,the Caucasus and Central Asia.At present,the research on the chemical composition of O.aegyptiaca is still blank in China.There are plenty of researches on the plants of Orobanche L such as O.coerulescens Steph,O.Pycnostachya and O.cumana Wallr.Scholars has proved that these plants contain a class of phenylethanoid glycosides compounds,which had found possese good activity in antioxidant,protecting liver,liver protection,anti-cancer,etc.In this study,by means of bioassay-guided separation,the chimical constituents and pharmacological activity of the O.aegyptiaca was studied for the purpose of providing detailed chemical and pharmacological information for the further development of O.aegyptiaca and its clinical application.Several higher content of phenylethanoid glycosides compounds were enriched and purified,on this basis,to establish the methods of UV to determination of total phenylethanoid glycosides and HPLC to determination of seven kinds of phenylethanoid glycosides for the first time.The twomethods is simple,feasible and can provide useful reference for the isolation and determination of phenylethanoid glycosides from O.aegyptiaca.By means of many chromatographic methods,including open column chormatography of silicagel,Sephadex LH-20,reversed phase ODS and pre-HPLC,twenty-four compounds were isolated from O.aegyptiaca.On the basis of physico-chemical data and spectral methods,twenty compounds were identified as poliumoside(1).3'-MeO-poliumoside(2).orobancheoside C(3).orobancheoside D(4).2-acetyl-poliumoside(5).3'-MeO-2-ace tyl-poliumoside(6).orobancheoside E(7).orobancheoside F(8).orobancheoside G(9).2-a cetyl-orobancheoside G(10).Acteoside(11).leucosceptoside A(12).orobancheoside H(13).martynoside(14).apigenin7-O-?-D-glucuronide(15).Chrysoeriol 7-O-?-D-glucuronide(16).(+)-syringaresinol-O-?-D-glucopyranoside(17).(+)-pinoresinol-O-?-D-glucopyranoside(18).(+)-isolariciresinol-4-O-?-D-glucopyranoside(19).(+)-lariciresinol-4-O-?-D-glucopyra noside(20);Among these compounds 3-4,7-10,13 were new compounds,and compou nds 1-4,6-10,12-20 were obtained for the first time from O.aegyptiaca,and compounds 3-4,7-10,13-16,19-20 were obtained for the first time from Orobanche L and O robanchaceae respectively.The methods of HPLC has been established for the determination of seven phenylethanoid glycosides for the first time.They were poliumoside,acteoside,2'-MeO-poliumo sdie,2-acetyl-poliumoside,orobancheoside F,2-acetyl-orobancheo side G and orobancheoside H.Among these compounds,poliumoside and 2-acetyl-poliumoside were the highest content.The methods of UV has been established for the determination of total phenylethanoid glycosides for the first time.With the highest content of 2-acetyl-poliumoside as the control substance,the content was determined.The two methods is simple,feasible and can provide useful reference for the isolation and determination of phenylethanoid glycosides from O.aegyptiaca.By means of DPPH methods,the antioxidant activity of eleven compounds were investigated,the results showed that three sugar phenylethanoid glycosides exhibit weaker antioxidant activity than disaccharide phenylethanoid glycosides,this is due to the steric hindrance effects.