New Tryptophan Metabolites from Cultures of the Lipophilic Yeast Malassezia furfur

Eleven new indole alkaloids were isolated from cultures of the human pathogenic yeast Malassezia furfur after addition of L‐tryptophan as the sole N‐source: pityriacitrin B (2), the malassezindoles A (3) and B (4), malassezialactic acid (6), the malasseziazoles A (7), B (8), and C (9), pityriazole (10), malasseziacitrin (11), and malassezione (12), along with the known d‐indole‐3‐lactic acid (=(αR)‐α‐hydroxy‐1H‐indole‐3‐propanoic acid 5), and 2‐hydroxy‐1‐(1H‐indol‐3‐yl)ethanone (13). The structural elucidation of these compounds was performed by spectroscopic methods (MS as well as 1D‐ and 2D‐NMR). The biogenetic relationships (Scheme) and biological activities of the new metabolites are discussed.