“…This lack of data might result from the general assumption that N-oxidation of tertiary amines is restricted to catalysis by a flavin-containing mono-oxygenase (EC 1.14.13.8). However, evidence has accumulated indicating involvement of cytochrome P-450 in amine oxide formation from certain types of aliphatic (Hallstr6m et al,198 lb), aromatic (Hlavica & Kehl, 1977; Hlavica & Hiilsmann, 1979), heteroaromatic (Schwartz et al, 1978; Gorrod & Damani, 1979;De Graeve et al, 1979) and alicyclic (Mattocks & White, 1971;Hallstr6m et al, 1981a) tertiary-amine substrates. In a previous paper (Hlavica & Aichinger, 1978) we reported on the formation, during cytochrome P-450-mediated metabolism of NN-dimethylaniline, of a product adduct absorbing at 448 nm that was attributed to binding to the pigment of the corresponding amine oxide. The present paper concerns the characterization of a spectral complex associated with mixed-function oxidation of pyridine.…”