Berkeleyamide C is a 4-pyridone isolated from the extremophilic fungus, Penicillium rubrum, collected from the Berkeley Pit Lake, Butte by Stierle and colleagues, University of Montana in 2007. The berkeleyamides were speculated to be formed biosynthetically from the condensation of a phenyl triketide with leucine. Berkeleyamide C differs from other members of the class by the presence of a 4-pyridone core structure with a 2-hydroxyethyl chain. Berkeleyamide C has demonstrated in vitro activity against caspase-1 and matrix metalloproteinase-3, which may be upregulated in many tumours.