Three New Pyrones With Antifungal Activity From Myrothecium verrucaria ACCC 38039

Myrothecium species have been recognized as prolific producers of biologically active secondary metabolites. Despite this, a substantial portion of their biosynthetic potential remains untapped. In this study, Myrothecium verrucaria ACCC 38039 was cultivated on a rice-based medium at 25°C for 30 days to explore its secondary metabolite profile. Seven compounds were isolated and purified by high-performance liquid chromatography, including three previously undescribed α-pyrone derivatives (compounds 1-3) and four known trichothecenes (compounds 4-7). The structures of these compounds were elucidated through one- and two-dimensional nuclear magnetic resonance spectroscopy and high-resolution electrospray ionization mass spectrometry. Among these newly identified pyrones, compound 1 exhibited notable antifungal activity, with a minimum inhibitory concentration of 16 µg/mL against both Aspergillus niger and Candida albicans, underscoring its potential as a promising lead compound for antifungal drug development.