Asperones A–E, five dimeric polyketides with new carbon skeletons from the fungus Aspergillus sp. AWG 1–15

Abstract

Asperones A–E (1–5), five dimeric polyketides with two distinct skeletons generated by the crucial [3 + 2] and [3 + 3] cycloadditions, were isolated from fungal metabolites of an Aspergillus sp. Their structures were established by spectroscopic data, chemical derivatization, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Compounds 2–4 showed significant nitric oxide (NO) inhibition in lipopolysaccharide (LPS)-induced RAW 264.7 macrophage cells, and exhibited IC₅₀ values of 16.0, 13.2, and 6.0 μM, respectively.