Talaromycesone A is an oxaphenalenone dimer recently isolated from a marine Talaromyces sp. by Imhoff and colleagues at the Centre for Ocean Research, Kiel, Germany. Talaromycesone A is structurally related to duclauxin and bacillosporin A. Talaromycesone A has potent antibacterial activity against human pathogenic S. aureus with IC50 3.70 µM. Talaromycesone A is a potent acetylcholinesterase inhibitor with IC50 7.49 µM.