Study On Extraction And Bioactivity Of Intracellular Polysaccharide From Funalia Trogii

Polysaccharides are one of the main energy substances required for life activities and are widely distributed in plants,algae,animals,fungi and other living organisms.In recent years,polysaccharides have received much attention because of their unique physicochemical properties and biological functions such as anti-tumour,antioxidant,anti-bacterial and hypoglycaemic.As a typical porous fungus,the crude extract of Funalia trogii has antioxidant and tumour cell proliferation inhibiting effects.In this study,the structural characteristics and biological activities of the intracellular polysaccharides of Funalia trogii were investigated.（1）In this study,mycelium was obtained by liquid fermentation of Funalia trogii,and then extracted of the intracellular polysaccharides（FCPs）by ultrasound-assisted hot water method using freeze-dried mycelium as raw material.The effect of sonication temperature,sonication power,material-to-liquid ratio and sonication time on the yield of intracellular polysaccharides was investigated by single-factor experiments,and the yield of intracellular polysaccharides was determined by phenol-sulphuric acid method.A Box-Behnken test design was carried out on the basis of single-factor experiments,using the polysaccharide yield as the response value.The analysis of variance（ANOVA）of the regression model showed that the effect of each factor on the polysaccharide yield was in the following order:temperature>power>material-liquid ratio>time.The optimum extraction process of intracellular polysaccharide was obtained by response surface optimization:ultrasonic temperature of 77℃,ultrasonic power of 335 w,material-to-liquid ratio of 1:26 and ultrasonic time of 31 min,and the yield of polysaccharide was 9.97%.（2）The intracellular polysaccharides obtained by ultrasonic extraction were deproteinated to obtain deproteinated intracellular polysaccharides（FDPs）.The FCPs and FDPs were structurally characterized by UV spectroscopy,FT-IR spectroscopy,I₂-KI reaction,Congo red experiment and scanning electron microscopy observation.The results showed that the FCPs had weak absorption peaks at 260 nm and 280 nm,this is,they contained small amounts of nucleic acids and proteins,while the FDPs had no obvious absorption peaks at 260 nm and 280 nm,this is,they contained almost no nucleic acids and proteins.Both polysaccharides contain longer side chains and more branches and both are triple helix conformation polysaccharides.The IR spectra of the FCPs and FDPs showed that they contained O-H,CH,CH₂,CH₃,C=O and C-O functional groups as well as pyranose rings and had characteristic absorption peaks of polysaccharides.（3）The in vitro antioxidant capacity of FCPs and FDPs was compared and both FCPs and FDPs had some reducing capacity（total antioxidant capacity）,which changed significantly with increasing concentration.The hydroxyl（·OH）scavenging ability of the two polysaccharides was more effective than the DPPH radical scavenging ability.The maximum scavenging rate of·OH was 94.13%and 87.89%for FCPs and FDPs,and the maximum scavenging rate of DPPH radicals was 63.87%and 59.05%.The cytotoxicity analysis and inhibit SW480 cells proliferation assay of the polysaccharides showed that both polysaccharides were almost non-cytotoxic and could effectively inhibit the SW480cell activity.The SW480 cells inhibition rate was 73.11%and 68.16%for FCPs and FDPs respectively at a concentration of 1 mg/m L.In conclusion,this paper determined the optimal process parameters for the extraction of Funalia trogii intracellular polysaccharides（FCPs）by ultrasonic-assisted hot water method.Structural characterization,antioxidant and antitumor analysis of FCPs and FDPs showed that the two polysaccharides belonged to triple-helix configuration polysaccharides and had high antioxidant and antitumor activities,which provides a certain theoretical basis for the research and development of Funalia trogii polysaccharides.