Keywords: Alkaloids / Fungi / Melanin / Natural products / Mycosis Exophialin, a previously unknown indole alkaloid, was isolated from the human-pathogenic fungus Exophiala dermatitidis upon cultivation on a medium containing tryptophan as sole nitrogen source. Its structure has been elucidated by 1D and 2D NMR experiments and mass spectrometry. When the mutant strain Mel-1 was used in place of the wild-type strain, the new indole alkaloid 8-hydroxyexophialin was generated