Geomycin B is a rare asterric acid derivative isolated from an Antarctic ascomycete fungus, Geomyces sp., by Che and collaborators at the Institute of Microbiology, Beijing, China in 2008. Structurally geomycin B is a trimeric compound comprising a central sulochrin depside flanked by two asterric acid diphenoxy bridges. Geomycin B displays significant antifungal activity against A. fumigatus (ATCC 10894) with IC50 0.86 µM.