[Metabolites of endophytic fungus Botryosphaeria ramosa L29 from Myoporum bontioides]

The endophytic fungus Botryosphaeria ramosa L29, isolated from Myoporum bontioides, was fermented, and its metabolites were separated and purified using chromatographic techniques, yielding nine compounds. Their structures were identified by spectroscopic methods as:(S,E)-6-(6-hydroxynon-3-en-1-yl)-2H-pyran-2-one(1), 5-hydroxy-8-methoxy-2-methyl-4H-chromen-4-one(2), 8-hydroxy-3-methyl-1H-isochromene-1-one(3), diaporthin(4), daldinione A(5), daldinione B(6),(4R)-O-methylsclerone(7), guhypoxylonol B(8), and 1, 8-dimethoxynaphthalene(9). Compound 1 is a new α-pyranone, and compounds 2 and 5-8 were isolated from the genus Botryosphaeria for the first time. Biological evaluation showed that compounds 2-4 showed weak antibacterial activity against Staphylococcus aureus, Escherichia coli O6, and E. coli O78. Compounds 1 and 8 showed weak activity only against S. aureus and E. coli O6, whereas compound 6 showed weak activity only against E. coli O6 and O78.