Studies On Chemical Modification And Bioactivities Of Water-insoluble Polysacchairdes From Dictyophora Indusiata

Dictyophora indusiata（Vent.Pers.）Fisch.is a rare edible fungi, which is well known forits high medicinal value such as treating diarrhea, reducing fat accumulation, down-regulatingblood pressure and anti-tumor activity. Polysaccharide is one of the active ingredients fromDictyophora indusiataand attracted more attentions. Currently, water-soluble polysaccharidesfrom Dictyophora indusiatawere extensively studied and its anti-bacteria, anti-oxidation,anti-tumor as well asimmune-modulation activities were confirmed. However, there were fewreports about the water-insoluble polysaccharide from the fruiting body of Dictyophoraindusiata. Due to its poor solubility, its chemical structure, physical-chemical properties andbioactivities still remains unknown.This work aimed to isolation, purification, characterization and bioactivity assay of thewater insoluble polysaccharide of Dictyophora indusiata. To improve the solubility of thepolysaccharide in water, it’s sulfated and phosphrylatederivatives were also prepared. Theeffects of modification on bioactivities were also studied. The main results of this work arelisted as follows:1. Water-insoluble polysaccharides （DIP） were extracted from the fruiting body ofDictyophora indusiata by alkali extraction and acid precipitation. The water-insolublepolysaccharides with sugar content was99.07%, and it could be dissolved in0.25mol/mLDMSO/LiCl solution. The chemical structure of DIP was characterized by gaschromatography （GC）, infrared absorption （IR） and¹³C nuclear magnetic resonancespectrometry (¹³C-NMR). The results indicated that DIP was a-（1â†'3）-D-glucan.2. Sulfated polysaccharides of Dictyophora indusiata （S-DIP） were prepared bychlorosulfonic acid-pyridine method, while phosphorylated derivatives （P-DIP） were preparedusing phosphoric acid as esterification reagent. S-DIPs with various substitution degrees, i.e.,0.584,0.989,1.549were obtained and named as S1-DIP,S2-DIP andS3-DIP, respectively.Similarly, P-DIPswith different substitution degrees i.e., P1-DIP （0.061）, P2-DIP（0.143）,P3-DIP （0.206）, were prepared as well.3. Anti-oxidation activity assayin vitro indicated that DIP having weak reducing poweragainst hydroxyl radical, DPPH radical scavenging, while both sulfated and phosphorylatedDPI derivatives having significant anti-oxidation activity.4. Anti-tumor activity assay in vitro showed that DPI has little effects on murinemelanoma B16cells and human breast carcinoma MCF-7cells growth, while both thesulfated and phosphorylated DPIs could significant inhibit BL16and MCF-17cell growth.Furthermore, sulfated DPIs have stronger activity than phosphorylated DPIs. And its activityincreased with the increasing of sulfation degress.