11‐ and 4′‐Epimers of Chaetomugilin A,Novel Cytostatic Metabolites from Marine Fish‐Derived Fungus Chaetomium globosum

11‐ and 4′‐epichaetomugilin A were isolated from a strain of Chaetomium globosum that was originally isolated from the marine fish Mugil cephalus. 11‐Epichaetomugilin A is the first compound to have an opposite absolute configuration at C(11) to that of other azaphilones isolated to date. Their absolute configurations were elucidated on the basis of spectroscopic analyses, including 1D‐ and 2D‐NMR techniques, and some chemical transformations. 11‐Epichaetomugilin A weakly inhibited the growth of cultured P388 cells and HL‐60 cells (IC₅₀ 88.9 and 66.7 μM , resp.).