Synthetic models for the active site of cytochrome P450

As cytochrome P450 models, two kinds of iron porphyrins were synthesized, each of which has an alkanethiolate axial ligand and hydroxyl groups inside the molecular cavities. The stable dioxygen adducts were obtained by the reaction of the ferric complexes with KO2 under an oxygen atmosphere. This study first demonstrated a hydrogen bond to bound dioxygen in an oxy form of a thiolate-coordinated heme model system. These results are discussed in relation to the process of dioxygen binding and activation in cytochrome P450. (C) 2002 Elsevier Science B.V. All rights reserved.