Isolation,Identification And Bioactivity Of Secondary Metabolites Of Duddingtonia Flagrans SF-170

Nematophagous fungi are natural enemies of nematodes and play an important role in the ecological balance of nature.As one of the important sources of antibiotics,the natural products of fungi have been widely studied.However,there are few studies on the secondary metabolites of nematode eating fungi.In this study,the secondary metabolites of the nematode eating fungus Duddingtonia flagrans SF-170 were preliminarily studied,and the biological activities of the compounds were determined,including antibacterial activity,anti-tumor activity and anti-nematode activity.30L fermentation was conducted for D.lagrans SF-170,a nematode fungi strain.The fermentation liquid was filtered and adsorbed with macroporous resin.The bacteria were extracted with ethanol,extracted with ethyl acetate,and concentrated to obtain 283 g extract.The structures of the compounds were identified by using one-dimensional and two-dimensional nuclear magnetic resonance(NMR),high resolution mass spectrometry(HRMS),infrared spectroscopy(IR),ultraviolet spectroscopy(UV)and electron circular dichroism(ECD).The identification showed that two of them were new compounds,This bicycle was named(1R,5S,6S)-5-hydroxy-1-(R,2E,6E)-1-hydroxy-3,7,11-trimethyldodeca-2,6,10-trienyl)-4-methyl-7-oxa-one(1)and(1S,2R,5S,6R)-2,5-dihydroxy-6-((2E,4Z,6E)-1-hydroxy-3,7,11-trimet Hyldodeca-2,4,6,10-tetraenyl)-7-oxacarboxo [4.1.0] Hept-3-en-3-yl)Methyl acetate(4),This compound is called(1R,6R)-5-hydroxy-6-(R,2E,6E)-1-hydroxy-3,7,11-trimethyldodeca-2,6,10-trienyl)-3-Methyl-7-oxaone(2).Perthylene-(2E,4E,6E)-1-hydroxy-3,7,11-trimethyldodeca-2,4,6,10-tetraenyl)-4-methylene-7-oxa-Heptane [4.1.0] Heptane-2,3,5-triol(5)and(1R,6R)-5-hydroxy 3-methyl-6-((2E,6E)-3,7,11-trimethyldodeca-2,6,10-trienyl)-7 The remainder,which was bicyclo[4.1.0] Hept-3-en-2-one(7),was known as oligosporol B(3)and 7-deacetoxyone A(6).The biological activity of other compounds except compound 5 was determined,and the results showed that it had no activity against staphylococcus aureus,candida albicans and escherichia coli.All the compounds showed moderate activity against human colon cancer cells HCT-116,human liver cancer cells HepG2 and human non-small cell lung cancer cells A549,among which combined 7 showed relatively good activity against the three tumor cells.Several compounds have no activity against Caenorhabditis elegans.The results of this study have important reference significance to improve the comprehensive utilization of nematode eating fungi.