Biohydroxylation of (−)-Ambrox®, (−)-Sclareol, and (+)-Sclareolide by Whole Cells of Brazilian Marine-Derived Fungi

A screening was performed using nine marine-derived fungi as biocatalysts and the natural products (−)-ambrox® (1), (−)-sclareol (2), and (+)-sclareolide (3) in order to select the microorganisms able to catalyze the biooxidation of these compounds. It was observed that only the Aspergillus sydowii CBMAI 934, Botryosphaeria sp., Eutypella sp., and Xylaria sp. presented active oxidoreductases and catalyzed the regioselective hydroxylation in the natural products. The hydroxylated metabolites obtained were 1β-hydroxy-ambrox (1a) (14 %, A. sydowii CBMAI 934); 3β-hydroxy-ambrox (1b) (17 %, Botryosphaeria sp.; 11 %, Eutypella sp.); 3β-hydroxy-sclareol (2a) (31 %, Xylaria sp.; 69 %, Botryosphaeria sp.; 55 %, Eutypella sp.); 18-hydroxy-sclareol (2b) (10 %, Xylaria sp.); and 3β-hydroxy-sclareolide (3a) (34 %, Botryosphaeria sp.; 7 %, Eutypella sp.). This is the first report of biohydroxylation of (−)-ambrox® (1), (−)-sclareol (2), and (+)-sclareolide (3) by whole mycelia of marine-derived fungi.