Angupyrones A - E, α-Pyrone Analogues with ARE-Activation from a Sponge-Associated Fungus Truncatella angustata.

TLC-DPPH guided fractionation of a sponge-associated fungus Truncatella angustata with a solid culture resulted in the isolation of five new α-pyrone-based analogues namely angupyrones A - E (1 - 5), and 3-ethyl-4-hydroxy-6-methyl-2-pyrone. Their structures were determined on the basis of extensive spectroscopic analyses, including the modified Mosher's method, bulkiness rule, and specific rotation for the configurational assignments. Angupyrones A - E exhibited moderate antioxidant response element activation in HepG2C8 cells, while the preliminary structure-activity relationship was discussed.