Biotransformation of dihydrocoumarin by Aspergillus niger ATCC 11394

Aspergillus niger ATCC 11394 was used to catalyze the biotransformation of dihydrocoumarin using two experimental conditions: growing and resting cells. Six biotransformation products (2- 7) were purified from the bio-reaction media and their structures elucidated by spectroscopic methods and mass spectrometry. The latter technique coupled to gas chromatography was used to analyze the time course of the biotransformations; from which results a metabolic pathway was proposed. The use of cytochrome P450 enzyme inhibitors, as well as working under poor oxygen conditions allowed us both to inquire about the type of enzymes involved in the process, and to design methods to prepare only metabolites that do not come from biological oxidations.