Study On The Chemical Constituents Of Xiye Polygala (Polygala Tenuifolia Wild.) On Sedative Effect

Background:Radix Polygalae is a traditional Chinese medicine, commonly used in clinical, recorded in the Chinese Pharmacopoeia (2005 version). And the sourse is from the dried root of the perennial herbage polygala tenuifolia Wild, or polygala sibirica L. family polygalaceae. The medicinal material is mainly distributed in the province of Shanxi, Shaanxi, Hebei, Hubei, Inner Mongolia, Shandong and other areas, besides, the largest output is from Shanxi and the best quality Shaanxi. It usually used as an sedative, expectorant, tonic, dementia preventing agent and subsiding swelling for the treatment of palpitation, amnesia, wet dream, insomnia, cough, sores ulceration and other illnesses.At present the main sedative drug is benzodiazepines which have a significant effect of sedative, hypnotic and anxiolytic, but also have shown a great deal of serious adverse reactions. Chinese tradional medicine has an advantage of less side effects, small toxicity, and non-addictive to treat anti-anxiety, and Polygala is a representative. Although Polygala has been mainly used as sedative drugs since the ancient times, domestic researches in this area are rarely reported. To develop and utilize of medical resources and study the material basis of Polygala, in this project under the guidance of pharmacological experiments, the activity screening was carried out on the extracts of different solvents, and then focused on its chemical composition which has shown the sedative effect. At last, good results have been achieved.Objectives:In order to develop and utilize of medical resources and study the material basis of Polygala, under the guidance of pharmacological experiments, we have taken out a series of studies on the chemical constituents of acid and alkaline hydrolysis products.Methods:In this study, to search the active sedative ingredient of Polygala, activity screening was carried out on the alcohol extracts of petroleum ether part, ether part, ethyl acetate part and n-butanol part respectively. Then, according to the pharmacological experiments above, on the basis of effective parts possible being flavonoids and saponins, the best extraction and seperation processes had been designed. Besides, we conducted a process investigation of pharmacodynamic. Through the pharmacological experiments, it is identified that saponins are the main active ingredients in the Polygala. Meanwhile we found that saponins Polygala have apparente adverse effects, mainly in the gastrointestinal reactions. In the pharmacological experiments, a large number of mice were toxic bleeding and gastrointestinal swelling. Thus, in our study, Polygalaceae saponins were respectively hydrolysed with acid and alkaline, which could obtain complete hydrolysis sapogenin and half-hydrolysis saponins, and then comparing the sedative activity and toxicity of complete hydrolysis sapogenin, half-hydrolysis saponin and saponins no-hydrolyzed. Using the methods of system solvent, repeated column chromatography and HPLC, we have taken out a series of studies on the chemical constituents of acid and alkaline hydrolysis products. All the structures were identified on the basis of physicochemical and spectrome.Results:1 the extracts of ethyl acetate part and n-butanol part had a significant sedative effect.2 sedative activity of saponin fraction in Xiye Polygala is higher than the flavonoid fraction.3 the toxicity of saponins were greatly decreased after hydrolysis, and comparing complete hydrolysis sapogenins and the half-hydrolysis saponins, the former were less toxic, but its sedative effect lower, too, indicating that toxicity of saponins has a great relationship with the glycosidic bond.4 In the end, seven compounds were obtained, among which the structure of five compounds were identified as 11-(5'-epxoy -4'- hydroxy - 3'-hydroxymethylcyclo -2'- hexenone)-△8(12)-Drimene(Ⅰ),Presenegenin(Ⅱ),presenegenin-(3)-O-β-D- glucoside(Ⅲ),3,4,5-trimethoxycinnamic acid (Ⅳ) and 2-Hydroxybenzoic acid(Ⅴ).Conclusions:In conclusion, the present study found that Xiye Polygala has a significant sedative active and the toxicity of saponins were greatly decreased after hydrolysis. Therefore, Xiye Polygala has good prospects on sedative active. In addition, further comprehensive investigations, should be carried out on the relationship between toxicity of saponins and the glycosidic bond.