Iron(II)porphyrin-Cyclodextrin Supramolecular Complex as a Carbon Monoxide-Depleting Agent in Living Organisms

The specific intermolecular interaction between an anionic tetraarylporphyrin and per-O-methylated β-cyclodextrin (TMe-β-CD) paved the way to produce a functional supramolecule that works as a strong carbon monoxide (CO)-depleting agent in living organisms. The supramolecular complex, hemoCD, that is composed of meso-tetrakis(4-sulfonatophenyl)porphinatoiron(II) and a TMe-β-CD dimer linked by a pyridine linker, captured internal CO from carboxyhemoglobin during its circulation in the blood of animals. HemoCD thus produced the pseudo-knockdown (loss-of-functional) state of endogenous CO in the animals. This unique property led us to investigate the biological function of endogenous CO as a gaseous signal mediator in living systems. In this paper, we introduce our recent study on the hemoCD complex as a biological CO-depleting agent.