Studies On The Active Metabolites Of Endophytic Fungus GP20 From Schisandra

Endophytic fungi are microorganisms which live within the tissues of host plants without causing external symptom. Some compounds with antibacterial and antitumor activities were contained in endophyte metabolites. Recently isolating activity compounds from endophyte metabolites is a hotspot for nature product chemistry.In this paper, an endophyte named GP20 was isolated from Schisandra chinensis (Turcz) Bail, which had high activities to inhibit bacterial and HepG2 cell. Issues such as the optimization of its fermentation, isolation and identification of the compounds with antibacterial and antitumor activity, species differentiation were studied. Conclusions are as follows:Preliminary study on the fermentation condition of GP20 strain, StapHlococcus aureus Rodenback was chosen as test bacterial. One-factor method was used with orthogonal experiment for the fermentation condition optimization. The results are as follows:The optimized cultural condition was that 1.0% glucose of carbon source, 1.5% peptone of Nitrogen source,7d of fermentation time,180r/min of rotation,40% of medium liquid volume,10% of inoculation amount,7.0 of initial pH value. The diameter of inhibition in optimized fermentation condition is increased by 3.5mm than which in initial fermentation condition.GP20 was fermented in large-scale, isolation was detected by antibacterial and antitumor, two compounds were obtained by solvent extraction, column chromatography, TLC and Prep-HPLC.Based on the data of spectral and comparison with related literatures,the compound 1 is 3-methylbenzene-1,2-diol-dextrose indicant; the structure of compound 2 can not be determined for little amount.The antibacterial and antitumor results indicated that the compound 1 showed high inhibiting activity to StapHlococcus aureus Rodenback, Listeria monocytogenes, Bacillus pumilus, Bacillus subtilis, the MIC were 19μg/mL,48μg/mL,50μg/mL and 35μg/mL respectively, compound 1 showed low inhibiting activity to HepG2 cell, the IC50 was 55μg/mL.Compound 2 had no activity to bacterial but showed medium inhibition to HepG2 cell, the IC50 was 25μg/mL.GP20 strain was identified by morphological characteristics and 18SrDNA sequence analysis. The results indicate that GP20 strain belongs to Paecilomyces lilacinus.This study indicated that GP20 metabolite contains several components with antibacterial activity and anticancer activity, and high value for the application of medical components obtained from secondary metabolites of endophytic fungi.