| Polygonatum sibiricum Redoute is a perennial herb of Liliaceae.It’s an important medicinal and edible homologous plant in our country.It’s rich in wild resources and contains active ingredients such as polysaccharides and saponins,which has high medicinal value.In this study,the extraction process,separation and purification process of Polygonatum sibiricum saponins were optimized,and the crude fractions were combined by chromatographic detection.On this basis,the antioxidant and hypoglycemic activities of the crude total saponins of Polygonatum sibiricum were analyzed,which laid a foundation for further development and utilization.The main research contents and results are as follows:1.The ultrasonic extraction method was used to extract the total saponins of Polygonatum sibiricum,and the process parameters were optimized by orthogonal test to determine the best extraction process of total saponins of Polygonatum sibiricum.The optimal extraction conditions of ultrasonic extraction method were as follows:solid-liquid ratio: 1:20(g/m L),extraction time: 1.5 h,ethanol concentration: 75%,extraction temperature: 55℃,ultrasonic frequency: 2 h,saponin yield: 7.8055±0.078mg/g.2.The ultrasonically extracted solution was filtered and concentrated under reduced pressure to the form of an extract to obtain ethanol-free extract of polygonum flavum.By the extraction method,the n-butanol extract of the target compound was finally obtained by concentrating it under reduced pressure.The total saponins of Polygonatum sibiricum were purified by macroporous resin method.First,the adsorption of macroporous resin was investigated,and the static adsorption time,sample concentration on the column,sample flow rate on the column,and sample volume on the column were determined by single factor test.The results showed that the sample concentration was 0.8 mg/m L,sample flow rate was 1 m L/min,and sample volume on the column was 3 BV.The adsorption rate of macroporous resin can reach more than 90%.The eluate was eluted with 4 BV of distilled water-30%ethanol-50% ethanol-70% ethanol-95%.After detection by thin-layer chromatography,the eluate was divided into six parts A,B,C,D,E and F,and the substance detection of different parts showed that the content of polysaccharide in parts A and B was higher.The results showed that polysaccharides and flavonoids were easily eluted by low concentration of alcohol solution,while parts C,D,E and F were eluted by high concentration of alcohol,which could obtain higher purity of total saponins.3.The gradient antioxidant and hypoglycemic activities of the four parts C,D,E and F with high content of saponins were studied.DPPH free radical,hydroxyl free radical and ABTS+ free radical scavenging ability of the total saponins of Polygonatum sibiricum was measured.Ascorbic acid(VC)was used as a positive control.The highest content of saponins,E fraction,could scavenge 63.48%,58.83 and 78.66% of the three free radicals,respectively,indicating that saponins had certain antioxidant activity,but the total saponins of Polygonatum sibiricum could scavenge the three free radicals less than VC.The inhibition rates of α-glucosidase and α-amylase of total saponins of Polygonatum sibiricum and acarbose were determined.When the concentration of acarbose was 2 mg/m L,the inhibition rates of the two enzymes were 99.32% and 96.36%,respectively.It’s further confirmed that the glucose-lowering activity of polygonosides was certain.4.The inhibition zone diameters of fraction E against Staphylococcus aureus,Escherichia coli and Bacillus subtilis were 16.58±0.34 cm,18.58±0.25 cm and9.42±0.42 cm,respectively.The inhibition zone diameters of fraction E were smaller than the positive control.The growth inhibition rate of fungal colonies was 59.74%,indicating that partial polygonoside E had a certain inhibitory effect on bacteria such as Staphylococcus aureus,Bacillus subtilis,Escherichia coli and fungi such as Botrysella cineracea.In conclusion,the ultrasonic extraction method of Polygonatum sibiricum saponin was optimized,and the yield of saponin was up to 7.8055±0.078 mg/g.By optimizing the adsorption performance of AB-8 macroporous resin,the adsorption rate of macroporous resin was evaluated,and the adsorptivity of the resin was fully utilized to obtain higher quality of refined total saponins.The antioxidant and hypoglycemic activities and antibacterial activities of total saponins of Polygonatum sibiricum were analyzed in vitro.This study provides a certain basis for the subsequent research on the pharmacological effects of Polygonatum sibiricum saponins. |
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