Aureonitol is a tetrahydrofuran isolated from Chaetomium sp. that acts like a transcriptional regulator for the biosynthesis of other secondary metabolites. The absolute configuration was confirmed in 2008. Aureonitol inhibits influenza A and B virus replication, being more effective against influenza A (H3N2) with EC50 of 100 nM. Aureonitol acts via inhibition of hemagglutination significantly impairing virus adsoption. Aureonitol has low cytoxicity with a IC50 value of 1426 μM.