Study On The Hypoglycemic Active Substances From Gynura Divaricata (L.) DC.

Gynura divaricata is a perennial herb of Compositae,also named as Dafeiniu,Shenxiancao,Jiumingcao,Baizicao,Fuguicao and etc.Gynura divaricata recorded as local medicine at first in “Standard of Chinese medicinal in Fujian province”(2006 edition),also detailed described in“Chinese medicine yinpian concocted norms in Fujian province”(2011 edition).Gynura divaricata is a commonly Chinese herb medicine for reducing blood glucose,its root,stem and leaf can be used as a medicine.Modern pharmacology study shows that it could significantly decrease the blood glucose of diabetic patient,but its material basis for the treatment of diabetes and its mechanism is not very clear,and should be in-depth research.In this thesis,using the method of system solvent,its 80% ethanol extract is divided into petroleum ether extract and ethyl acetate extract and n-butanol extract and aqueous solution of four different polar parts.Doing toxicological and pharmacological screening,obtain active fractions based on 3T3-L1 adipocytes insulin resistance model induced by dexamethasone as stimulus.MTT method was used to detect the toxicity on 3T3-L1 adipocytes of four extract.The in vitro reducing sugar fuction and its mechanism of extracts were observed by GOD-POD,ACS-POD and GPO-PAP assay on 3T3-L1 adipocytes insulin resistance model,respectively.The result showed that n-butanol extract and aqueous solution have biological active for anti-hyperglycemic.It also demonstrated that drug effect by high concentrations in 24 h can induce the cultured glucose concentration increased 24.5% and 27.5%,FFA concentration of supernatant were significantly decreased 9.9% and 13.1%,whereas intracellular triglyceride concentration were increased 31.8% and 39.3% as compared to the control grop.Therefore,the active fractions that n-butanol extract and aqueous solution can regulate sugar metabolism and lipid metabolism by improved 3T3-L1 adipocytes of insulin resistance.In order to explore material foundation of Gynura divaricata,adoptting silica gel column chromatography,gel permeation chromatography,MCI and HPLC column chromatography separation,8 compounds were isolated from the activity fractions of n-butanol extract.Among them,4 compounds were furtherly identified on the basis of chemical,spectral technologies and related article,they respectively are β-sitosterol glucoside-6′-O-heptadecoicate(1),methyl nicotinate(2),nicotinic(3),stigmasterol-3-O-β-D-glucopyranoside(6).Then compound methyl nicotinate was first isolated from this plant.Doing toxicological and pharmacological screening on monomers are similar with fractions screening,obtain active monomers based on 3T3-L1 adipocytes insulin resistance model as stimulus.The results show that compound 4 and compound 5 have a certain anti-hyperglycemic activity.It demonstrated that compound 4 and compound 5 effect by high concentrations in 24 h can induce the cultured glucose concentration increased 6.2% and 4.0%,FFA concentration of supernatant were significantly decreased 10.6% and 9.5%,whereas intracellular triglyceride concentration were increased 12.0% and 10.3% as compared to the control grop.