Studies On The Chemical Components Of Three Stereum Species

The fungi of Stereum mainly distribute in the tropical or subtropical regions, and they can produce varieties of metabolites with diverse structures, displaying a broad range of biological activities. In our study, the abundance of the compounds of four fungi in Stereum has been compared in different media. Three of them, Stereum sp. YMF1.1686, Stereum insigne CGMCC 5.57 and Stereum sp. YMF1.02608 were cultured with a better medium, and then the chemical components of the three fungi have been studied. The nematicidal and antibacterial activities of the compounds have been further tested. The results were as follows:Sixteen compounds were isolated from the EtOAC extract of the fermentation broth and methanol extract of mycelium of the fungus Stereum sp. YMF1.1686. Eight compounds including sterostrein R (4), sterostrein T (6), sterostrein H (7), sterostrein U (8), sterostrein A (9). sterostrein C (10), sterostrein S (11) and sterostrein V (12) were identified. Except for compounds 4,8,11 and 12, the others were obtained from the former documented Stereum.Ten compounds were isolated from the EtOAC extract of the fermentation broth and methanol extract of mycelium of the fungus S. insigne CGMCC 5.57. Seven compounds:4-hydroxybenzaldehyde (2), methyl ester-(9Z,11E)-9.11-hexadecadienoic acid (4), (R)-5-((3-methylbut-2-en-1-yl)oxy)-2-(prop-1-en-2-yl)-2,3-dihydrobenzofuran (5), stela sterol (6), ergosterol peroxid (7) (3β,5α,6α,22E)-3-hydroxy-5,6-epoxy-7-one-8(14),22-dien-ergost (9) and (3β,5α,6β,22E)-7,22-diene-3,5,6-triol-ergosta (10) were identified. Among these compounds, compound 5 is novel, and the others are known.Five compounds were isolated from the extract of the solid culture medium of fungus Stereum sp. YMF 1.02608, and four compounds:methyl ester-(9Z, 11E)-9,11-hexadecadienoic acid(1),3β,5α,9α-trihydroxy-ergosta-7,22-dien-6-one(3), ergosterol peroxid (4) and (3β,5a,6a,22E)-3-hydroxy-5,6-epoxy-7-one-8(14), 22-dien-ergosta (5) were identified. All of the four compounds are known.All compounds isolated from these three fungi have been assessed for the nematicidal and antibacterial activities, and there were no obvious function.The dominant innovation point of the study is the isolation of four new sesquiterpenes from the fungus Stereum sp. YMF1.1686 and one novel compound from the fungus Stereum insigne CGMCC 5.57.