Fig. 6. Reduced cytochrome P450 enzymes with 20-(R)-1.

A CYP17A1/20-(R)-1 complex after reduction by sodium dithionite yields a split Soret with maxima at 429.5 and 454 nm (brown initial spectrum), which exhibits little reoxidation even in air over 105 min. B CYP3A4/20-(R)-1 complex after reduction by sodium dithionite also yields a split Soret with maxima at 428 and 454 nm (brown), which slowly re-oxidizes to the original 437.5  nm (purple, 103 min) in air over the same time period. C CYP2D6/20-(R)-1 complex after reduction by sodium dithionite yields maxima at 431 nm and 455 nm (initial brown spectrum), which re-oxidizes in air to the original 437 nm over the same time period.