Studies On The Extraction, Purification, Antioxidant Activities And Biological Activities Of Polysaccharide Of Exocarpium Citri Grandisthis

This study use exocarpium citri grandisthis of XiuShui as raw material.Themicrowave extraction technology in the application of exocarpium citri grandisthispolysaccharide extraction was investigated. The separation and purification method weredetermined. The antioxidant activities of the crude ECP in vitro and its purified fractionswere evaluated by determinations of their reducing power and scavenging activities on1,1-Diphenyl-2-picrylhydrazyl free radicals(DPPH·);hydroxyl radicals (·OH);2,2-biphenyl2-biphenyl-double (3-ethyl benzene and Margaret lin-6-sulfonic acid radicals (ABTS·+).The dephlogisticate, antitussive and expectorant effects in mice were identified. The mainconclusions are listed as follows:1. Investigate the microwave extraction technology in the application of ECPextraction.Analyze the influence of process paramaters---liquid to solid ratio,microwavepower,microwave temperature,microwave time on the yield of exocarpium citri grandispolysaccharide. Based on the response surface analysis with the Design-Expert softwareprogram, the extraction condition of the microwave for exocarpium citri grandispolysaccharides was optimized. The Optimal microwave extraction conditions were: liquidto solid ratio was70, microwave power was546.56W, microwave temperature was100℃,microwave time was22.32min.Under these conditions，the exocarpium citri grandisthispolysaccharides yield can reach24.64%.2. Crude polysaccharide of exocarpium citri graudis was extracted by boiling water.The filtrated polysaccharide was precipitated by alcohol. The protein in ECP was removedby Sevage method. The small molecular impurities were removed by dialysis. Two purifiedpolysaccharides ECP1and ECP2were obtained from crude ECP by DEAE-52anion-exchange chromatography. The polysaccharide contents of ECP, ECP1and ECP2were74.29%、83.9%and85.7%, respectively. The molecular weight of ECP1and ECP2were34460and89690.Which determination by GPC-MALLLS.3. The antioxidant activities of the crude ECP in vitro and its purified fractions wereevaluated by determinations of their reducing power and scavenging activities onDPPH·,·OH and ABTS·+. Crude polysaccharide and its purified fractions had goodantioxidant activities, and their antioxidant activities were significantly correlated withtheir concentrations. Our results suggest that the antioxidant activity of ECP2is higherthan those of ECP1and ECP.4, The model of edema induced by xylene in mice was used to observe thedephlogisticate effect. The model of cough induced by concentrated ammonia water inmice was used to observe the antitussive effect.The model of phenel red execretion inmice was used to observe the expectorant effect; The ECP could inhibit the edema induced by xylene in mice. The swelling inhibition rates in low, middle and high dose group were24.93%,34.84%and48.72%. The swelling inhibition rate in the positive control groupwas52.83%. The ECP could prolong cough incubation period and reduce the cough timesin2minutes induced by concentrated ammonia water. There was significant difference (P<0.01) between the control group and the middle and the high dose group except the lowdose group.Which means the ECP could increase phenel red execretion in mice. Theresults show that the ECP have a significant dephlogisticate, antitussive and expectoranteffects.