Extraction And Structural Analysis Of Polysaccharides In The Fruiting Body Of Dictyophora Indusiata And Their Bioactivities

The present study focused on the extraction and structural analysis of polysaccharides in the fruiting body of Dictyophora indusiata and their bioactivities. The antioxidant activities about water-soluble polysaccharides were investigated in vitro and in vivo. The immune activities of acid- and alkali-soluble polysaccharides were investigated in vitro and in vivo. The main contents and results are as follows:The fruiting bodies of Dictyophora indusiata from 6 different regions, including Gutian, Jianyang and Shunchang in Fujian province, Jiangshan in Zhejiang province, Guiyang in Guizhou province, and Honghe in Yunnan province, were investigated. The contents of crude proteins, crude fat, crude fiber, crude polysaccharides, ash, mineral elements and amino acids were determined. It's showed that the fruiting bodies from different regions all enriched crude proteins, crude polysaccharides and crude fiber with low crude fat, although, there was a marked difference in crude polysaccharides. The content of crude polysaccharides from Jiangyang in Fujian procince was 30.68% when the sample of Guizhou was about 18.68%. The fruiting bodies of Dictyophora indusiata were rich in essential mineral elements such as Ca , Mg, Fe and Zn. The most abundant samples were the samples from Zhejiang and Guizhou. By amino acid analysis, the limited amino acid of Dictyophora indusiata was lysine and it's changing with the origins.Aiming at optimization of the extraction of polysaccharides in the fruiting body of Dictyophora indusiata response surface methodology was adopted. The efects of extraction temperature,material-solvent ratio and extraction pH on the yield of polysaccharides were measured by single factor test and response surface method using the extraction rate as index.The optimal conditions were determined as follows:extraction temperature 95℃,material-solvent ratio 1:33 and extraction pH 2.0.Under the optimal conditions,the extraction rate of polysaccharides from Dictyophora indusiata was 11.71%.And the actual extraction rate of the polysaccharides was detected as 11.698%.High in vitro antioxidant activities of polysaccharides from Dictyophora indusiata were observed in antioxidant systems.Its DPPH and ABTS scavenging capabilities were both in dose-dependent manner, with EC50 values being of 0.150 mg/mL and 0.909 mg/mL, respectively.The water-soluble crude Dictyophora indusiata polysaccharides (DIP)were extracted from the fruiting body of Dictyophora indusiata. They were fractionated by Sephadex G-75 and DEAE-Sepharose fast flow column chromatography to obtain DIPs I and II. The structural features of DIPs I and II were investigated. The results indicated that DIP I was composed of Fru, Glc and Man with molecular weight of 2100.99 kDa , while DIP II comprised Xyl, Fru, Gal, Glc and Man with molecular weight of 18.16 kDa. The glycosidic linkage of DIP I was composed of terminal Man: terminal Glc:→1)-Glc-(6→:→1)-Man-(3,6→with the ratio of 1.0:9.3:5.6:1.0, while DIP II was composed of→1)-Xyl-(5→:→1)-Gal-(3→:→1)-Gal-(6→:→1)-Glc-(6→:terminal Glc :→1)-Man-(2→with the ratio of 10.8: 1.0: 37.2: 18.7: 2.4: 13.7. DIP exhibited the higher antioxidant activities in vivo and vitro assay systems and could be explored as a novel potential antioxidant.The acid- and alkali-soluble polysaccharides (DIPs I and II)were extracted from the fruiting body of Dictyophora indusiata in this work. DIP I comprised of Glc, Fru and Man, whereas DIP II was of Glc and Fru. Glc was the dominant monosaccharide in both DIPs with relatively molar percentage of > 60%, which constructed the backbone of polysaccharide chain. The analysis of glycosidic linkage indicated that Glc was occurred as→1)-Glc(-6→in DIP II. The immunological assays showed that both DIPs I and II had a noticeable effect on hemolytic antibody level in the tested dosage range.