X-ray analysis confirmed the configuration of the title N1-alkylated C
4-nitroimidazole inhibitor. The plane of the imidazole ring, sitting o
n an axis of the trityl propeller, bisects the angle between two pheny
l rings, while the nitro group extends over the third. Modeling of the
interactions between the cytochrome P450 and the title compound (C22H
17N3O2) has been performed on the basis of the crystal structures of 1
-trityl-4-nitroimidazole and bacterial cytochrome P450(BM-3) The repla
cements and deletions in the sequence of the latter has been performed
to match mammalian cytochrome P450-IIIA1. The modeling explained why
inhibitors with a C4-substituted imidazole ring showed lower effectivi
ty than those without substituents, as an additional group of atoms at
C4 prevents close interactions of the imidazole ring with the heme Fe
atom.