Two New Polyketide Compounds from the Endophytic Fungus Trichoderma spirale A725 of Morinda officinalis

Six polyketides were isolated from the fermentation broth of an endophytic fungus Trichoderma spirale A725 of the medicinal plant Morinda officinalis by silica gel, reversed phase silica column chromatography, sephadex LH-20 and high performance preparative liquid chromatography. Their structures were elucidated to be 6-hydroxy-4-isopropyl-1,8-dimethyl-spiro[4.5]deca-1,8-dien-7-one (1), 2-hydroxy-2,5-dimethyl-7-oxo-5,7-dihydro-2H-furo[3,4-b]pyran-4-carboxylicacid (2), 3ethyl-4-hydroxy-6-methyl-2H-pyran-2-one (3), harzialactone A (4), 3-hydroxy-5-(4-hydroxybenzyl)dihydrofuran-2(3H)-one (5), and 4-acetyl-3-hydroxy-6-methyl-pyran-2-one (6) on the basis of extensive spectral analysis. Among them, compounds 1 and 2 were new compounds, and compound 3 was a new natural product. Moreover, the cytotoxicities of compounds 1 similar to 6 were evaluated against four cancer cell lines (Hep G-2, MCF-7, SF-268 and A549). However, none of them exhibited cytotoxic activity against the tested tumor cells.