Studies On Isolation, Purification And Its Secondary Metabolites Bioactivity Of Endophytic Fungi From C. Pilosula,T.lanceolata And H. Corniculata

Endophytic fungi are a kind of microbial communities which are widely distributed in plants. The study found that endophytic fungi can not only live in harmony with the host plants, but also produce a number of good biological active substances available to the host. Codonopsis pilosula(Franch.) Nannf., Thermopsis lanceolata R. Br. and Halenia corniculata(L.) Cornaz are both the medicinal plants,commonly used in traditional Chinese medicine formula. This article was focused on the three kinds of endophytic fungi and their biological activities.A total of 73 endophytic fungi were isolated from three plants by tissue culture method. 15 strains of endophytic fungi were identified by morphological and molecular biological methods. They are distributed in Alternaria 、 Aspergillus 、Penicillium、Alternaria、Mucor、Botrytis and Pythium.A total of 219 samples of ethyl acetate, normal butanol and methanol from three plant species were determined. The results showed that the antibacterial activity of the ethyl acetate fraction generally good than the butanol and methanol fraction. In ethyl acetate fraction, Endophytic fungi Cp-R-12 from the root of C. pilosula had the best bacteriostatic ability. Five test bacteria inhibition zone were both between the 20-25 mm. The MIC value of E. coli reached 0.125 mg/mL.A total of 219 samples of three plants of endophytic fungi were tested for antioxidant activity. Results show that,in the total reduction force experiment, 22 samples with Vc equivalent had more than 200 μg/mg. Among them, the antioxidant activity of the endophytic fungi Tl-R-6 and Cp-R-8 ethyl acetate was the best, and the Vc equivalent was 618 μg/mg and 513 μg/mg, respectively. Hydroxyl free radical scavenging experiment, clearance rate in more than 45% of the samples had two,Cp-R-8 and Cp-L-2 ethyl acetate fraction. By comparing IC50 with Vc, the hydroxyl radical activity of Cp-R-8 and Cp-L-2 ethyl acetate parts was determined to be better than Vc. DPPH free radical scavenging experiment, a total of 4 samples of the clearance rate of more than 90%, its IC50 value was less than Vc. The scavenging ability of the 4 samples to the DPPH radical scavenging capacity was lower than that of the Vc.In the inhibition of α-glucosidas experiment, the inhibition rate of 15 samples was more than 90%. Among them, C. pilosula endophytic fungi Cp-S-2 ethyl acetate IC50 value reached 0.4075 mg/mL. However, the positive control of acarbose in lowIC50 value to 0.0293 mg/mL.C. pilosula endophytic fungi Cp-R-8 exhibited good antioxidant andα-glucosidas inhibitory activity and the fermentation products chemical constituents were isolated. In the end, 1 compound was isolated from the ethyl acetate fraction,which was identified to β-sitosterol.