Four novel dihydroisocoumarin (=3,4-Dihydro-1H-2-benzopyran-1-one) glucosides from the fungus Cephalosporium sp. AL031

Four novel dihydroisocoumarin (=3,4-dihydro-1H-2-benzopyran-1-one) glucosides were isolated from a culture broth of a strain of the fungus Cephalosporium sp. AL031. Their structures were elucidated as (2E,4E)-5[(3S)-5-acetyl-8-( beta-D-glucopyranosyloxy)-3,4-dihydro-6-hydroxy-1-oxo-1H-2-benzopyran-3-yl]penta-2,4-dienal (1), (2E,4E)-5-[(3S)-5-acetyl-8-(beta-D-glucopyranosyloxy)-3,4-dihydro-6-methoxy-1-oxo-1H-2-benzopyran-3-yl]penta-2,4-dienal (2), (3S)-8-(beta-D-glucopyranosyloxy)-3-[(1E,3E,5E)-hepta-1,3,5-trienyl]-3,4-dihydro-6-hydroxy-5-methyl-1H-2-benzopyran-1-one (3), and (3S)-8-[ (6-O-acetyl-beta-D-glucopyranosyl)oxy]-3-[(1E,3E,5E)-hepta-1,3,5-trienyl]-3,4-dihydro-6-methoxy-5-methyl-1H-2-benzopyran-1-one (4) by spectroscopic methods, including 2D-NMR techniques and chemical methods.