Liver-cell protective pyridones from the fungi Tolypocladium album dws120.

Five previously undescribed pyridone derivatives, tolypyridones I–M, were identified from the solid rice medium fermented by Tolypocladium album dws120, along with two known compounds tolypyridone A (or trichodin A) and pyridoxatin. Their planar structures and partial relative configurations have been determined by careful interpretation of their spectroscopic data. The full assignment of the relative and absolute configurations of tolypyridones I–M was achieved by gauge-independent atomic orbital 13C NMR calculation, quantitative nuclear Overhauser effects based interatomic distance calculation, and electronic circular dichroism calculation. In addition, we have fully determined the configuration of tolypyridone A by X-ray diffraction analysis. In bioassay, tolypyridones I was able to restore cell viability and inhibit the release of alanine aminotransferase and aspartate aminotransferase for ethanol-induced LO2 cells, suggesting its potential as a liver protective agent. [Display omitted] • Seven pyridones were identified from Tolypocladium album dws120. • Relative configurations were determined by 13C NMR calculation and quantitative NOE analysis. • Tolypyridones I showed protective effects against ethanol-induced LO2 cell injury. [ABSTRACT FROM AUTHOR]