Geomycin C 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 C is a trimeric compound comprising a central sulochrin depside flanked by asterric acid diphenoxy and aspirocoumaranone subunits. Geomycin C is active against Staphylococcus aureus and Streptococcus pneumoniae and the Gram-negative bacterium Escherichia coli.