Unguinol is a depsidone isolated from Aspergillus unguis by researchers at the USDA in 1972. In the same year, Swedish researchers produced unguinol by fermentation of a strain of A. nidulins in chloride-depleted media. Unguinol exhibits weak antibacterial activity but its pharmacology has not been extensively investigated. A discovery screen of fungal extracts identified unguinol as an inhibitor of C4 plant enzyme pyruvate phosphate dikinase (PPDK), a potent herbicide target.