Analysis Of Nucleoside Changes And Antioxidant Activity During Subculture Of Ophiocordyceps Sinensis

Ophiocordyceps sinensis is a traditional and valuable tonic Chinese medicine with various effects such as immunomodulation,anti-tumor and anti-fatigue.O.sinensis,as an asexual type of O.sinensis,the mycelium has similar chemical composition and pharmacological efficacy with its wild type.There are many studies on the characteristics of O.sinensis,but for the differences between O.sinensis from different regions and the characteristics of O.sinensis degeneration are not yet known.To address these problems,this experiment aims to collect fresh O.sinensis from different regions of China and isolat asexual strains of O.sinensis from different regions,compared the differences between the mycelium of each strain,and take strain YS-CS211117 as an example to investigate the characteristics of different generations of O.sinensis.1.The evolutionary relationships of O.sinensis and its related fungi were analyzed by constructing NJ phylogenetic trees based on ITS sequences of eight strains of O.sinensis and its related fungi.The differences between the O.sinensis isolated from artificial O.sinensis and other wild O.sinensis are relatively greater.The evolutionary distances between O.sinensis and its related fungi are,in descending order,Tolypocladium,Fusarium,Roesleria,Penicilium,Truncatella,Cladosporium,Epicoccum,Juxtiphoma,Coprinus,and Mortierella.2.The solid culture conditions of O.sinensis were optimized with biomass as the index,and the results of single-factor experiments showed that the optimal nitrogen source was beef paste,the optimal carbon source was glucose,and the optimal inorganic salt ion was magnesium sulfate.Using glucose,beef paste,magnesium sulfate and vitamin B₁ content as the investigated horizontal factors and other medium components as auxiliary investigating factors,the optimal medium obtained by designing orthogonal experiments was:potato 300g/L,beef paste 4 g/L,glucose 40 g/L,magnesium sulfate 0.15 g/L,vitamin B10.05 g/L,chloramphenicol 0.1 g/L,potassium dihydrogen phosphate 0.1 g/L Where glucose was the largest influencing factor in growth.3.Qualitative and quantitative analysis of six nucleosides,namely,uridine,guanosine,inosine,adenosine,cytidine and cordycepin,in the mycelium of eight O.sinensis was carried out by HPLC.Guanosine,uridine and adenosine were the most important nucleosides in all O.sinensis mycelium samples,with the highest content of adenosine in LT and the lowest content of adenosine in LZ.uridine was the highest in HS and LT,and the lowest in LZ.The differences of inosine content among the mycelial samples were not significant,cytidine content was the highest in YS,and cordycepin content was very low in each sample.The DPPH radical scavenging power,ABTS radical scavenging power and total reducing power activities of the eight strains of O.sinensis from different sources were different,with the Litang and Heshui samples having stronger DPPH scavenging power,ABTS scavenging power and total reducing power activities,and the Linzhi sample having the worst activity.4.The distribution of nucleoside analogues and the magnitude of antioxidant activity during the succession culture of strain YS-CS211117.The amount of mycelium reached the peak in the 3rd generation among the 6passages.The characterization of nucleoside components showed that O.sinensis had the most total nucleoside components under CS-2d and relatively low nucleoside components in the 3rd generation.The results of the three antioxidant activity regimes of the six passaged mycelium samples showed that all the 2nd generation mycelium samples had the strongest activity,and the antioxidant activity gradually decreased with the increase of generations.