Dihydroisocoumarins and a tetralone from Cytospora eucalypticola.

Two dihydroisocoumarins, 3,5-dimethyl-8-hydroxy-7-methoxy-3,4-dihydroisocoumarin and 3,5-dimethyl-8-methoxy-3,4-dihydroisocoumarin were isolated from a culture filtrate of Cytospora eucalypticola, together with three known dihydroisocoumarins and a tetralone derivative. Their structures were determined by spectroscopic methods. These isocoumarins are mildly antifungal, and antibacterial towards gram positive bacteria. A known compound, 5-hydroxymethylmellein, showed mild antifeedant activity towards Spodoptera littoralis.