Study On The Composition Analysis And Antioxidant Activity Of Ethanol Extract From The Roots Of Suaeda Salsa

ObjectiveSuaeda salsa（S.salsa）is an annual plant of Suaeda genus in Chenopodiaceae,with a variety of bioactive components.In this study,the roots of S.salsa was used as the experimental object to optimize the optimal extraction technology of total alkaloid from ethanol extract.The chemical constituents of the extract were isolated and identified,and conduct a preliminary study on its antioxidant activity in vitro.MethodsThis paper is based on the single factor experiment,the total alkaloid yield of was used as response value to investigate the effects of four factors,including solid-liquid ratio,ethanol concentration,extraction temperature and extraction time.Response Surface Methodology（RSM）was used to optimize the total alkaline root raw alkali extraction technology,the Design-Expert 8.0.6software experiment Design and analysis of experimental data.Medium pressure preparative liquid chromatography,Sephadex LH-20 column chromatography,normal phase silica gel column chromatography and semi-preparative high liquid chromatography were used for separation and purification,and the structures were identified by NMR spectroscopy.In this paper,the reducing ability of identified chemical constituents from the roots of Suaeda salsa was determined,and the antioxidant activity of DPPH radical,hydroxyl radical and superoxide anion scavenging ability was investigated in vitro.ResultsThe optimal extraction conditions of total alkaloids from the roots of Suaeda salsa were as follows:solid-liquid ratio of 1:24.626 g/mL,ethanol concentration of 85.478%,extraction temperature of 78.195℃,extraction time of 2.088 h.Under these conditions,the yield of total alkaloids was0.520%.Combined with the actual conditions,the extraction conditions were adjusted as follows:solid-liquid ratio of 1:25 g/mL,ethanol concentration of86%,extraction temperature of 78℃,extraction time of 2.1 h.The average yield of total alkaloids was 0.521%±0.04%,which was basically consistent with the prediction,and proved the feasibility of the optimized process.In this paper,the extracts were further separated by medium pressure preparative chromatography,Sephadex LH-20 column chromatography,normal phase silica gel column chromatography and semi-preparative high performance liquid chromatography and other modern chromatography separation,at the same time,using nuclear magnetic resonance spectrum technology(¹H-NMR,¹³C-NMR)to identify the structure,four main compounds were isolated and identified,compound 1:berberine,compound 2:（-）-episyringaresinol,compound 3:hydnocarpin,compound 4:7S,8R-dihydrodehydrogenationconiferyl alcohol.Compounds 1-4 were isolated from Suaeda salsa for the first time.The antioxidant activity of four compounds in vitro with L-ascorbic acid as the control was tested.The total reducing power of berberine,the scavenging power of DPPH radical and superoxide anion were stronger than those of the other three compounds.The hydroxyl radical scavenging ability of（-）-episyringaresinol and berberine was slightly stronger.In general,the chemical constituents in the roots of Suaeda salsa have certain antioxidant activity.ConclusionsIn this study,the extraction conditions of total alkaloids from the roots of Suaeda salsa were optimized,four chemical components were isolated and identified,and antioxidant activity of the four compounds was studied through in vitro antioxidant experiments,which provided a theoretical basis for further development of Suaeda salsa resources and clinical practice.