Studies On The Secondary Metabolites Of Stereum Complicatum And Stereum Gausapatum

Metabolites from the genus Stereum are diverse,and the structural types of these metabolites include sesquterpenoids,benzoic ring substituents,benzofurans,steroids,sterols,fatty acids,etc.Among them,sesquiterpenoids are the most abundant,and many of these sesquterpenoids have new skeletons and bioactivities.In this study,two fungi Stereum complicatum ATCC60953 and Stereum gausapatum ATCC60954 were used to isolate and identify their secondary metabolites,and the nematocidal activity,the antibacterial activity and anti-tumor activity of compounds were studied.The results are as follows:Seven compounds were isolated and identified from the fermentation products of Stereum complicatum ATCC60953.They are sterostrein P(m60953-1),butyl-2,4-hydroxy-6-methylbenzoate(m60953-2),orsellinic acid(m60953-4),isoeverninic acid(m60953-7),5,7-dihydroxy-6(3-methylbut-2-enyl),isobenzofuran-1(3H)-one(m60953-8),2-carboxy-5-methylfuran(m60953-13)and 5-methyl-2-furanol(m60953-19).They are all known compounds.Five compounds were isolated from the fermentation products of Stereum gausapatum ATCC60954.They are strobilol E(m954-1),stereumin D(m954-7),strobilol L(m954-8),strobilol N(m954-12)and strobilol O(m954-14).Compounds strobilol L(m954-8),strobilol N(m954-12)and strobilol O(m954-14)are new metabolites.All isolated compounds were assayed their biological activity.The experimental results showed that compound m60953-2 isolated from S.complicatum ATCC60953 could kill 77.9%nematode Meloidogyne incognita at 200 μg/mL in 24 h,but it had no toxic activity to nematode Caenorhabditis elegans at the same concentration.Compounds m60953-7 and m60953-8 showed nematicidal activity against C.elegans when the two compounds mixed(1:2;m/m)at the total concentration at 200 μg/mL,but the two compounds had no activity when they assayed separately.Compound m60953-1 had antibacterial activity against Staphylococcus,aureus.Compound m954-12 isolated from S.gausapatum ATCC60954 killed 75.8%C.elegans with 200 μg/mL at 48 h.Compound m954-1 had weak antibacterial activity against S.aureus.All isolated compounds had no antitumor activity.