Chaeglobocinnin A and Chaeglobokojin A: Chaetoviridin Azaphilone–Cinnamic Acid and −Kojic Acid Hybrids with Anti-Liver Fibrosis Activity from an Endophytic Chaetomium globosum

Two unprecedented azaphilone hybrids─chaeglobocinnin A (1) and chaeglobokojin A (2)─featuring chaetoviridin-type cores coupled with cinnamic acid and kojic acid, respectively, were isolated from an endophytic fungus Chaetomium globosum. 1 features a 6/6/6/6 fused tetracyclic framework with a benzene ring attached as a pendant moiety. 2 possesses an unprecedented 6/6/5/6/6 pentacyclic system characterized by a spiro moiety. Their structures were unequivocally established by comprehensive spectroscopic analysis, NMR calculations with DP4+ probability analysis, and single-crystal X-ray diffraction. Additionally, 2 exhibited antiliver fibrosis activity via inhibition of the TGF-β/Smad signaling pathway.