Study On The Mechanisms And Effects Of Glycyrrhiza Flavonoid To Improve The Intracellular Saponin Of Paecilomyces Cicada

Cordyceps cicada is an edible and medical fungus with high nutritional and medicinal value.Its saponins are the main bioactive substance with anti-tumor,anti-cancer,hypoglycemic and immunomodulatory effects.However,the shortage natural resources of C.cicadae and the extremely difficult culture of C.cicadae with environment's impact,long growth cycle and low productivity result in that C.cicadae cannot meet the market demand.Paecilomyces cicada was the fungus to form C.cicadae.Its submerge culture can overcome these shortcoming.The biomass of P.cicadae obtaining from submerged culture possesses the similar function with C.cicadae and becomes the substitute of C.cicadae.In the dissertation,the culture media and condition that the flavonoids of Glycyrrhiza uralensis?FG?increase the synthesis of the intracellular saponin of P.cicadae?IPS?was optimized.The increase mechanism of FG,antioxidant power and the ability to inhibit the two starch hydrolase was studied.The results are as follows:?1?After compared with many herbs contianed flavonoids,Glycyrrhiza uralensis was believed as the herb to increase IPS yields markedly and FG was further confirmed to significantly increase IPS synthesis.The optimal medium included xylose 2%,fructose 6%,glycerol 4.47%,zein 0.9%,bran 5%,rhubarb rice 5%,CuSO₄ 0.06%,FG 0.18%.The best culture condition was inoculum volume 17%,culture time 120 h,culture temperature 24.2°C,rotary speed 180 rpm,medium capacity 120 mL.The IPS yields reached 4.589±0.323 g/100mL in the optimal medium and under the best culture condition.?2?The thin-layer chromatography exhibited that IPS without FG?PS?has only3 compositions and IPS with FG?LPS?has 7 compositions.The antioxidant activity analysis implied that The DPPH·scavenging rate and hydroxyl radicals generation inhibition rate and ferric reducing antioxidant power?FRAP?of the LPS improved9.6%,10.08%,25.98%than those of the PS respectively.The kinetics model analysis demonstrated that the improvement of DPPH·scavenging rate and FRAP was depended on the maximum reaction velocity and the affinity for PS or LPS to the substrate.The inhibition of IPS or PS to hydroxyl radicals generation was a mixed type dominated by competitive inhibition.The test to inhibit starch hydrolase activities indicated that the?-glucomannase and?-amylase inhibition rate of LPS were significantly improved.The kinetics model analysis exhibited the increase of?-glucomannase and?-amylase inhibition rate depended on the affinity for these two starch hydrolases to substrate.The inhibition of?-glucomannase and?-amylase by IPS was a mixed type dominated by competitive suppression.?3?The transcriptomics technique was used to study the expression difference of genes of P.cicadae resulted from FG.GO analysis of different genes revealed that the different genes caused by FG were involved in metabolic process,single-organism process and cellular process,regulatory genes related with catalytic activity,binding;controlling genes expression in cell and cell part.KEGG metabolic pathway analysis of differential genes indicated that different genes participated in global and overview maps,amino acid and carbohydrate metabolism pathway;translation metabolism pathway.In kegg metabolic pathway,the up-regulated genes included hexokinase,glucose-6-phosphate isomerase,fructose-bisphosphate aldolase,pyruvate dehydrogenas,L-lactate dehydrogenase;citrate synthase,succinate dehydrogenase,8-amino-7-oxononanoate aminotransferase,dethiobiotin synthetase,hydroxymethyl-glutaryl-CoA synthase,sterol 14?-demethylase,methylsterol monooxygenase,?⁷-sterol 5-desaturase.