Biotransformation of (-)-camphor by Salmonella typhimurium OY1002/2A6 expressing human CYP2A6 and NADPH-P450 reductase

In a previous in vitro study, (-)-camphor (1) was examined by incubation with human liver microsomes, and the oxidative metabolites thus formed were analyzed using gas chromatography-mass spectrometry. However, thus far, no large-scale biotransformation using recombinant human P450 has been performed. Here, the biotransformation of compound 1 has been investigated by using Salmonella typhimurium OY1002/2A6 expressing human CYP2A6 and human NADPH-P450 reductase as a biocatalyst. Compound 1 (400 mg) was converted to (1S,5S)-(-)-5-exo-hydroxycamphor (2) (30.4 mg) and (1S,7S)-(-)-8-hydroxycamphor (3) (2.4 mg) by S. typhimurium OY1002/2A6. This is the first report to show that large quantities of metabolites 2 and 3 can be produced by S. typhimurium OY1002/2A6 expressing human CYP2A6 and NADPH-P450 reductase.