Biotransformation of citronellol by means of horseradish peroxidase

Oxidation of citronellol by means of a horseradish peroxidase-hydrogen peroxide system in the presence of ascorbic acid has been studied. Incubations have been performed in two-phase medium (water-ethyl acetate or water-citronellol) and in homogeneous solution (water-methanol). The influence of pH, incubation time, hydrogen peroxide excess, and enzyme concentration on citronellol conversion and composition of the reaction products has been determined. The main oxidation products were isolated and identified. They were different from compounds formed during the sensitized photooxidation of citronellol. This seems to exclude the participation of singlet oxygen in reactions mediated by horseradish peroxidase.