Study On Extraction Process,Stability And Biological Activity Of Total Saponins Of Aralia Elata

Aralia elata is a medicinal and edible plant that contains many active ingredients such as saponins,flavonoids,and polysaccharides.It has extremely rich pharmacological effects.And saponins are the main functional active ingredients in Aralia elata.In this paper,using Aralia elata sprouts as raw materials,this study analyzes the extraction method and purification process of saponins from Aralia elata.Liquid chromatography-mass spectrometry is used to analyze the composition of saponins from Aralia elata.And studies the stability,antioxidant activity andα-glucosidase inhibitory activity of Aralia elata.The results are as follows:1.The response surface method is used to optimize the ultrasonic extraction method and the ultrasonic-assisted aqueous two-phase extraction method.By comparing the extraction rate and in vitro antioxidant activity of the two extraction methods,the best extraction process is determined.The best process parameters of ultrasonic extraction method are:71.00%of ethanol concentration,1:72（g/m L）of material-liquid ratio,40 min of ultrasonic time,and saponin extraction rate is 36.51 mg/g.The scavenging rates of DPPH free radical and ABTS free radical are 72.97%and 71.71%,respectively.The best technology of ultrasonic-assisted aqueous two-phase extraction method are:24%of ammonium sulfate concentration,22%of ethanol concentration,30 min of ultrasonic time,and saponin extraction rate is 36.27 mg/g.The scavenging rates of DPPH free radical and ABTS free radical are 83.33%and 81.51%,respectively.The results show that the two extraction methods have little difference in the content of saponins,but extracted by the ultrasonic-assisted aqueous two-phase method have stronger antioxidant activity than the ultrasonic extraction method.In this paper,the ultrasonic-assisted aqueous two-phase method is selected to extract the total saponins of Aralia elata for purification and preparation experiments.2.The macroporous resin method is used to purify the saponins of Aralia elata,and the sample concentration,sample volume and elution method are determined through single factor test.The loading concentration is 0.25 mg/m L,the loading volume is 10 BV,and the saponin adsorption rate is 92.87%.After removing impuritiws with water and 30%ethanol,the 70%ethanol eluate is collected to obtain the purified solution of Aralia elata saponin after purification.The total saponin content after purification is 63.23%.By measuring the changes of saponins content of Aralia elata saponins under different conditions,the effects of temperature,p H and light on the stability of saponins of Aralia elata are studied respectively.The results show that temperature have little effect on the content of total saponins of Aralia elata.Under the condition of strong acid and alkali,it have a destructive effect on the content of saponins.Under the condition of avoiding outdoor sunlight,the total saponins of Aralia elata are more stable.The purified saponins are separated and identified by liquid chromatography-mass spectrometry.Three compounds are identified as aralia saponins A,aralia saponins V and aralia saponins II.3.PNPG is used as a substrate to determine the inhibition test of the purified Aralia elata saponins and acarbose onα-glucosidase in vitro.The IC₅₀value of the total saponins of Aralia elata is 0.391 mg/m L,The IC₅₀value of the acarbose is 0.041 mg/m L.When the concentration is 2 mg/m L,the inhibitory rate of saponins of Aralia elata onα-glucosidase is96.71%,the inhibition rate of acarbose onα-glucosidase is 87.65%.By studying the enzymatic kinetics of Aralia elata saponin and acarbose onα-glucosidase,it is proved that Aralia elata saponin is a non-competitive inhibitory type,and acarbose is a competitive inhibitory type.The antioxidant activity of Aralia elata saponin is evaluated by measuring the scavenging rate of DPPH and ABTS free radicals.The experimental results show that when the concentration of total saponins of Aralia elata is 1.6 mg/m L,the scavenging rate of total saponins of Aralia elata on DPPH free radical is 93.33%,and the scavenging rate of ABTS free radical is 92.26%.