Abstract Four fungal melanins were degraded by potassium persulfate, a new, mild chemical oxidation method. The percentage of degradation varied from 15 to 50% calculated by weight loss. Analysis of the degradation products by gas chromatography showed numerous fatty acids, both straight and branched chain, in widely varying amounts. The n‐C 16 and n‐C 18 acids were present in greatest abundance. By two‐dimensional thin‐layer chromatography, several phenols and anthraquinones were noted.