Dicerandrols, new antibiotic and cytotoxic dimers produced by the fungus Phomopsis longicolla isolated from an endangered mint

Bioassay-guided fractionation of the organic extract from a culture of Phomopsis longicolla, an endophytic fungus of the endangered mint Dicerandra frutescens, led to the isolation of dicerandrols A, B, and C. Extensive NMR and HRFABMS experiments were used to identify these new yellow antibiotic and cytotoxic compounds as 2,2 ' -dimeric tetrahydroxanthones.