Studies On The Secondary Metabolites Of Stereum Fasciatum And Stereum Rugosum

Fungi of the Stereum can result in the isolation of a great diversity of secondary metabolites,which have various structures and show different biological activities.In this study,we investigated the secondary metabolites of two fungi of Stereum,which were Stereum fasciatum CGMCC5.54 that was purchased from China General Microbiological Culture Collection Center(CGMCC)and Stereum rugosum ATCC64657 that was purchased from American Type Culture Collection(ATCC).We compared their growth in different media and detected the abundance of the metabolites of two fungi by a way of Thin-Layer Chromatography(TLC).The secondary metabolites of the two fungi have been studied,the all compounds isolated from the two fungi have been further tested their nematicidal,antibacterial and antifungal activities.The results obtained were as follows:Ten compounds were isolated from ethyl acetate extract of PDB culture broth of the fungus S.fasciatum CGMCC5.54.Six compounds stereumene A(1),stereumene B(2),stereumene C(3),9Z-octadecenoic acid(4),2-hydroxy-4-methylbenzoic acid(8)and 1-methyl-4-(5-methyl-1-methylene-4-hexen-1-yl)-cyclohexene(10)were identified.Compounds 1,2 and 3 are novel secondary metabolites.Twelve compounds were isolated from the ethyl acetate extract of MEB culture broth of the fungus S.rugosum ATCC64657.Nine compounds sterostrein W(1),5-hydroxymethyl-2-furancarboxaldehyde(2),sterostrein P(3),orsellinic acid(4),orcinol(6),sterostrein H(8),agrocybin D(9),sterenin H(10)and sterostrein V(11)were identified.Compounds 1 and compound 11 are new sesquiterpenes.All compounds obtained from the two fungi have been tested their nematicidal,antibacterial and antifungal activities.Stereumene B isolated from S.fasciatum CGMCC5.54 exhibited nematicidal activity against Caenorhabditis elegans at the concentration of 200 ?g/mL;and the compound 2-hydroxy-4-methylbenzoic acid isolated from S.fasciatum CGMCC5.54 exhibited weak nematicidal activity against C.elegans at the concentration of 400 ?g/mL.Compound sterostrein W isolated from S.rugosum ATCC64657 exhibited inhibitory activity against Bacillus subtilis,which showed minimal inhibitory concentration(MIC)at 400 ?g/mL.