Figure 1 - Model system for selective oxidation by cytochrome P450.

The enzyme model contained an oxidizing metal and multiple binding functionalities (cyclodextrins, shown as conical toroids). The model for a steroid substrate contained terminal, hydrophobic moieties that could be bound by the cyclodextrins, bringing the C6 -proton in position for selective hydroxylation (product shown in red) by the tetrameric cyclodextrin complex²¹.