We investigated complexes formed between bilirubin and transition or rare-earth elements, and their relative stabilities. Relativeratesof complex formation were analogous to metalloporphyrin and metal complex stabilities, according to the Irving-Williams series. Transition metals that formed strong, square planar complexes caused rapid bilirubin degradation. Iron(II) was oxidized to iron(IlI) i...

Abs t r a : The most fiequently encountered function of cytochromes P450, the monooxygenation of substrates, is now well understood and depends on the involvement of a high-valent iron-0x0 intermediate. The corresponding reactions have been reproduced by using metalloporphyrin model systems, the most efficient catalysts being Fe(III) or Mn(III) tetraarylporphyrins bearing electronwithdrawing su...