P450 Compound I observed

One of the most elusive compounds in bio(inorganic)chemistry is posed by Compound I, a highly reactive possible intermediate in the catalytic cycle of cytochrome P450 enzymes. These enzymes are involved in the metabolism of approximately 75% of known pharmaceuticals. Rittle and Green have now characterized compound I for one particular cytochrome P450 enzyme, CYP119, as reported in Science, and introduced by Stephen Sligar.