Bioactive Penicipyrrodiether A, an Adduct of GKK1032 Analogue and Phenol A Derivative, from a Marine-Sourced Fungus <i>Penicillium</i> sp. ZZ380

Penicipyrrodiether A, an adduct of GKK1032 analogue and phenol A derivative, was isolated from a culture of marine-associated fungus Penicillium sp. ZZ380 and represents the first example of this type of fungal metabolite. Its structure was elucidated by extensive spectroscopic analyses, including 1D- and 2D-NMR, HRESIMS, MS/MS, and electronic circular dichroism calculation as well as single-crystal X-ray diffraction. Penicipyrrodiether A showed antibacterial activity in inhibiting the growth of methicillin-resistant Staphylococcus aureus with a MIC value of 5.0 μg/mL. Its plausible pathway for biosynthesis has been proposed.