Catalytic effect of cytochrome c on H ₂ O ₂ oxidation of a p -hydroxyphenyl-substituted BODIPY derivative

As a peroxidase, cytochrome c (Cyt-c), could catalyze the oxidation of a p -hydroxystyryl-substituted BODIPY derivative (BOH) induced by H 2 O 2 through the oxidation of the C=C bond in the p -hydroxystyryl functional group. The stable structure of BOH was calculated that the BODIPY basic structure with a p -hydroxystyryl group which led to the fluorescence emission of BOH was perpendicular to the benzene ring containing a carboxyl group. The compounds containing ferriporphyrin have the catalytic effect on the reaction of BOH + H 2 O 2 . However, there is no catalytic effect on the reaction of BOH + H 2 O 2 of the porphyrin ring without Fe, Fe 2+ and Fe 3+ . It shows that the coordination between Fe and N (Fe−N coordination) plays a central role in the peroxidase-like catalysis of the oxidation of BOH by H 2 O 2 . Interestingly, hemoglobin (Hb) and myoglobin (Mb) also act as catalysts for the oxidation of BOH by H 2 O 2 . However, the catalytic rates of hemoglobin (Hb) or myoglobin (Mb) on H 2 O 2 oxidation of BOH are lower compared to those of Cyt-c. This difference in reactivity might be attributed to the use of Cyt-c from horse heart in its reduced form with the five-coordinate structure, and the significant steric hindrance effect resulting from variations in the distribution positions of −CH 2 −CH 2 −COOH groups and the iron porphyrin rings, as revealed by crystal structure analysis. This study might have practical significance for the p -hydroxystyryl-substituted BODIPY derivative in the application of catalytic oxidation and fluorescence sensing.