(+)-Fenchone, a bicyclic monoterpene, is widely distributed in plants and found in essential oils from Foeniculum vulgare. This component has camphoraceous fragrance. (+)-Fenchone is used as a food flavour and in perfumes. Although, there are report that (+)-fenchone has toxic. P450 enzymes are shown to detoxify and/or toxify these compounds to metabolites more polar and sometimes more reactive metabolites. (+)-fenchone are oxidized to 6-endo-hydroxyfenchone, 6-exo-hydroxyfenchone and 10-hydroxyfenchone derivatives in human liver microsomes. CYP2A6 is suggested to be a principal enzyme in catalyzing (+)-fenchone 6-exo and 6-endo hydroxylation by human liver microsomes. 10-Hydroxylation of (+)-fenchone is also metabolized by CYP2B6.