Investigation Of Preparation Process Of Perylenequinonoid Form An Endophytic Aspergillus Fumigatus SPS-02

Endophytic fungi are one of important rich sources of dug lead compounds.Previous studies had revealed that an endophytic fungus Aspergillus fumigatus SPS-02 derived from the medicinal plant Artemisia annua Linn,was found to produce perylenequinone,a novel type of photosensitizer.This thesis mainly focused on isolation and identification of this compound,biological evaluation,and the optimization of the fermentation process.Firstly,the fungus A.fumigatus SPS-02 was cultured in 7%Salt Czapek Medium.One secondary metabolite was isolated from ethyl acetate extract of the culture broth by HPLC and identified as8-chloro-3,6a,7,9,10-pentahydroxy-9,8,7,6a-tetrahydroperylen-4（6aH）-one by a combination of spectroscopic methods,including 1D and 2D-NMR and MS.It was the first report that perylenequinone chloride was obtained from Aspergillus fumigatus.In vitro bioassay showed that perylenequinone chloride has potent antibacterial activity against E.coli（ATCC 25922）and C.albicans（ATCC 10231）with MIC values of 0.78 and 1.56μM.In addition,perylenequinone chloride exhibited moderate antiproliferative activity against the A549 cell line with an IC₅₀0 value of 12.79μM.Secondly,based on the yield of perylenequinone chloride,the fermentation process was optimized by single-factor method,orthogonal and response surface experiments,and the 7%salt Czapek liquid medium was used as the basic medium.The optimal fermentation medium composed of sucrose 30 g,K₂HPO₄ 1 g,NaNO₃ 4 g,MgSO₄ 0.5 g,KCl 0.5g,FeSO₄ 0.01 g and NaCl 70 g in 1L water.The optimal fermentation conditions were as follows:the temperature 30℃,fermentation time 9.4 d,initial pH 7.5,shaking table speed 200 rpm.The yield of perylenequinone chloride was found to raise up to 0.926 mg/L as compared with the initial yield（0.429 mg/L）.The results of this thesis may provide theoretical basis for the large-scale production of perylenequinone chloride.