Studies On Secondary Metabolites And Activities Of Paecilomyces Gunnii

Paecilomyces gunnii is an asexual form isolated from the C.gunnii complex.According to reports,Cordyceps gunnii is a large cordyceps with similar pharmacological effects to Cordyceps sinensis,and the extract of Paecilomyces gunnii has the functions of enhancing immunity,analgesia,sedation,enhancing memory and lowering normal body temperature.Up to now,there are few reports on the secondary metabolites and their activities of Paecilomyces gunnii.It is a hot spot in the research of microbial natural products that the active secondary metabolites in microorganisms are explored through the screening of culture conditions and optimal separation techniques.In this thesis,a strain of Paecilomyces gunnii YMF1.00003 was used as the research object.By screening the culture conditions,the optimal conditions were selected to further expand fermentation.The traditional separation technology and LC-MS guiding were used to find the microbial secondary metabolites.The structures of the compounds was determined by analysis of spectral data（NMR,MS,Optical Rotation and UV）,and their activity was assayed.The crude extract was analyzed by LC-MS and TLC,and the optimized conditions of Sabouraud solid medium was selected for fermentation the Paecilomyces gunnii;HPLC,column chromatography,gel chromatography,TLC and other methods to separate and purify its metabolites.The structure of the compound was identified by high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy,and the structures of 23 compounds were determined.Among them,m3pg-25,m3pg-29,m3pg-30,m3pg-37 a,m3pg-37 b and m3pg-54 are new polyketones,named as Guniiketones A-F,respectively.Their configurations will be further identified by circular dichromatography（CD）.m3pg-28 and m3pg-40 are polyketone type compounds.m3pg-1,m3pg-2 and m3pg-3 were fatty acid compounds,m3pg-13,m3pg-14,m3pg-15 and m3pg-16 were steroids.Steroidal compounds have high oxidation and cytotoxic activity to be tested.Polyketones are to be tested for neuroprotective and cytotoxic activities.Four compounds（m3pg-29,m3pg-37,m3pg-54）and（m3pg-28,m3pg-40）isolated from P.gunnii YMF1.00003 were tested for tumor cytotoxicity and neuroprotective effect,and the nematocidal activity of compounds m3pg-54 was tested.