A novel quinone antibiotic named malbranicin was isolated from the cul
ture filtrate and mycelium of Malbranchea cinnamomea TAIM 13T54, a the
rmophilic fungus. The antibiotic was elucidated to be cetylethyl)-2-me
thoxy-2,5-cyclohexadiene-1,4-dione by spectral analysis. Malbranicin e
xhibited antimicrobial and cytotoxic activities against Gram-positive
bacteria and mammalian cell lines, respectively.