Study On The Phosphorylation Modification Of Pleurotus Ostreatus And Its Structure And Liver Protection

Pleurotus ostreatus is a common dietetic Chinese herb in China.It has a long history of cultivation in china because its delicious flavor is widely loved by the public.Pleurotus ostreatus is rich in polysaccharides and polysaccharides is also one of the main active ingredients of Pleurotus ostreatus.However,Pleurotus ostreatus polysaccharides(POP)cannot exert its effective effect in the cell tests because of its solubility problem.The structural modification of polysaccharides can change the spatial configuration and biological activity.The molecular modification of POP has rarely been reported at home and abroad.So this experiment aims to optimize the phosphorylation modification process by using Pleurotus ostreatus polysaccharides as research object and explore the in vitro antioxidant activity and basic structural features preliminarily.Then we studied the protective effect of PPOP on liver injury induced by carbon tetrachloride in male Kunming mice deeply.The main conclusions are as follows:(1)The POP were extracted by hot water.Then we researched four facts which have greater impact on phosphorylation by single factor experiments and deal the orthogonal test.The best phosphate modification process is:sodium tripolyphosphate:sodium trimetaphosphate=6:1,reaction temperature 90?,reaction time 3 h,solution pH=9.The phosphorylation grafting amount modified by this method is 9.824%.The method is simple and easy,and the phosphate content is high.(2)After separated by DEAE-52 and G-100,POP was divided into POP-A and POP-B and PPOP was divided into PPOP-A,PPOP-B and PPOP-C.The UV spectrum indicates that phosphating has an effect on the maximum aborption wavelength of UV.The Congo red test showed that POP does not contain a multi-strand structure while PPOP has multi-strand structure.FT-IR showed that PPOP retained the characteristic absorption peak of polysaccharides after phosphate esterification,and the absorption peaks of P=O and P-O-C were detected.The ESEM showed that PPOP was fragmented,the shape was curled,the fragments were irregular and the internal forces were reduced.The molecular weight test proved that the average molecular weight of PPOP-A,PPOP-B and PPOP-C was 17kDa?64kDa and 81 kDa.HPLC experiments showed that PPOP was mainly composed of 67.9%galacturonic acid and 26.1%xylose.PPOP-A consists of 92.3%galacturonic acid and 7.6%xylose.PPOP-B consists of 41.8%galacturonic acid and 57.8%xylose.PPOP-C consists of 6.0%rhamnose,6.3%xylose acid and 86.8%galacturonic.(3)An in vitro antioxidant test was carried out on the POP and PPOP.The DPPH test showed that the scavenging rate of DPPH free radicals was 79.85%when PPOP was 1 mg/mL,which was higher than 57.35%of the same concentration POP.The ·OH radical test showed that when PPOP was at a concentration of 1 mg/mL,the scavenging rate of ·OH reached 79.48%,which was higher than 42.09%of POP at the same concentration.The O2-·test showed that the O2-·scavenging rate of PPOP was 82.52%at a concentration of 1 mg/mL.The ABTS+ test proved that when the PPOP concentration was 1 mg/mL,the clearance rate for ABTS+ reached 88.97%,which was higher than 75.43%of POP at the same concentration.The reducing power test verified that the reduction ability of PPOP is stronger than POP.(4)The results of mouse experiments showed that PPOP has stronger hepatoprotective effect and antioxidant activity in vivo than POP.Different concentrations of PPOP and POP were used to pretreat mice.The body weight of the mice was improved.The number of blood cells increased.The degree of swelling of the liver was relieved.The concentrations of TC,TG and LDL-C were decreased,and the concentrations of HDL-C and ALB were increased.The levels of ALT,AST,and AKP in mice serum were decreased.T-AOC,CAT,T-SOD,and GSH-PX activities of the liver were increased,and the content of MDA decreased.Pathological studies showed that PPOP protect hepatocytes better than POP.