Studies On Metabolites Of Endophytic Fungus LN-15 From Melia Azedarach L.

The endophyte is a huge community that shears a great proportion in fungus family. Researches have indicated that some endophytes may produce various metabolites with novel structure and bioactivity. Due to this, extensive attention has been paid to chemistry and biology of endophyte both in China and abroad.Melia azedarach L. is a kind of defoliate trees belonging to Meliaceae. Lots of researches on Meliaceae show it contains various high effective insecticidal components, which lead to its broad insecticidal spectrum. Endophytes can produce identical or similar metabolites with their host plant. In order to screen for bioactive metabolites, fermentation broths of the strain Sphaceloma sp. LN-15 isolated from Melia azedarach L were investigated. This paper dealt with the ethyl acetate extracts of fermentation broths and the mycelium, respectively. Silica gel column chromatography, reversed-phase chromatography and Sephadex LH-20 were employed. Four compounds (W-1, W-2, W-3, W-4) were isolated from the EtOAc extracts of fermention broths, and other two (W-5, W-6) from mycelia, respectively. Their structures were elucidated on the basis of spectroscopic analysis including EI-MS, FAB-MS, 1H-NMR and 13C-NMR. They were identified as ergosta-4,6,8(14), 22-tetraen-3-one(W-1),5α,8α-epidioxy-(22E,24R)-ergosta-6,22-dien-3β-ol(W-2), didodecyl 3-3"-disulfanediyldipropanoate(W-3),pregnadienol-oneacetate(W-4),α-palmitic-glycerolester (W-5).These five compounds (W-1~W-5) were for the first time isolated from Sphaceloma sp., and compound W-3, W-4 were first obtained from the endophytes of Melia azedarach L. Compound W-6 was a mixture that consisted of the homologous compounds.