Isolation,Purification,Structure And Physiological Activity Of Polysaccharides From Sophorae Fructus

Sophorae Fructus is the mature fruit of Sophorajaponica L.It’s a traditional Chinese medicine with a long history of application.Sophorae Fructus has the functions of dispelling wind and heat,cooling blood and stopping bleeding,clearing heat and reducing fire,etc.It is included in the Pharmacopoeia of the People’s Republic of China.The main active constituents in Sophora Fructus are flavonoids and isoflavones,alkaloids,polysaccharides,etc.In this dissertation,the Sophorae Fructus polysaccharides were used as the research object to optimize the extraction conditions,isolation and purification,structural characterization,monosaccharide composition and determination anti-oxidation activities,hypoglycemic and antibacterial activities.Main results are listed as follows:1.Research on extraction conditions,isolation and purification of crude Sophorae Fructus polysaccharide(CSFP)Based on the yield of crude polysaccharides,the factors of water-to-raw ratio,enzyme dosage,enzymatic hydrolysis time and ultrasonic time were analyzed by single factor test.The response surface Box-Behnken was applied to CSFP extraction optimization.Design-Experts 8.0.6 was used to statistical analysis,obtained the optimal conditions as follows:water-to-raw ratio 20 mL/g,enzyme addition 0.45%,ultrasonic time 33 min,and enzymatic hydrolysis time 50 min.It was verified that the CSFP yield was 12.24%and the glucose content was 28.91%obtained under these conditions.The Sevage reagent and DEAE-52 cellulose chromatography column were used to separate and purify the CSFP to three components of Sophorae Fructus polysaccharide(SFP),SFP-1 and SFP-2.2.Structure and components analysis of polysaccharide from sophora fructusMulti-angle scattering light spectroscopy with gel permeation chromatography(MALS-GPC),fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),high performance liquid chromatography-evaporative light scattering detector(HPLC-ELSD),gas chromatography-mass spectrometry(GC-MS)was used to analyze the structural characterization of polysaccharides from sophora fructus.The monosaccharide composition and molar ratio of polysaccharide SFP are Xyl:Ara:Fru:Rha:Man:Gal:Glu:GluA=1.00:7.39:2.25:1.65:27.65:32.11:66.15:9.57,the SFP-1 components and molar ratioare Xyl:Ara:Fru:Rha:Man:Gal:Glu:GluA=1.00:4.88:2.26:2.45:24.32:29.98:89.79:6.48.3.Study on physiological activity of SFP,SFP-1 and SFP-2Antioxidant study of SFP,SFP-1 and SFP-2 were carried out by free radical evaluation.The effects of polysaccharides on ABTS+,O2-,OH-and DPPH free radicals were investigated.The results showed that SFP,SFP-1 and SFP-2 had poor ability to scavenge O2-,while showed strong ability to scavenge ABTS+,OH-,DPPH free radicals.SFP and SFP-1 have the effect of preventing DNA damage.The results of inhibition activity on α-glucosidase and a-amylase showed that SFP,SFP-1 and SFP-2 had a strong inhibitory effect on a-glucosidase,while the inhibitory effect on a-amylase was not obviously.The results of α-glucosidase kinetics experiments indicated that the inhibition type of SFP-1 was a reversible competitive inhibition type,and SFP and SFP-2 belonged to a reversible mixed inhibition type.Antibacterial activity of SFP,SFP-1 and SFP-2 were studied by punch method.The study indicated that SFP,SFP-1 and SFP-2 have better inhibitory activity on Staphylococcus aureus and Bacillus subtilis than Escherichia coli.In addition,SFP-1 and SFP-2 antibacterial activity better than SFP.