Enhancement of catalytic efficiency of metalloporphyrin-reductant-molecular oxygen biomimetic system by aminoacid external ligands

The presence of aminoacid external ligands (Cys and His) markedly increases the efficiency (in terms of reaction rate constant and turnover number) of the metalloporphyrin-reductant-molecular oxygen catalytic system in cholesterol oxidation reactions; in so doing, Cys contained systems are more active co-catalysts showing a pronounced maximum of concentration dependence profiles.