Ochrasperfloroid, an ochratoxin-ergosteroid heterodimer with inhibition of IL-6 and NO production from Aspergillus flocculosus 16D-1

摘要

A novel ochratoxin-ergosteroid heterodimer, ochrasperfloroid (1), together with a known mycotoxin, ochratoxin A (2), were isolated from the sponge-derived fungus Aspergillus flocculosus 16D-1. The structure of 1 was determined on the basis of 1D/2D NMR, HRESIMS/MS, and LC-UV/MS analysis of its alkaline hydrolyzates, quantum-chemical C-13 NMR calculation, and comparison with literature data. Of note, the ergosteroid embedded in 1 is also a new structure. Ochrasperfloroid (1) showed potent inhibitory activity towards IL-6 production in lipopolysaccharide (LPS)-induced THP-1 cell line, with an IC50 value of 2.02 M, and NO production in LPS-activated RAW264.7 macrophages, with an IC50 value of 1.11 M.