hemehematin

Hemehematin, commonly referred to as hematin, is the ferric complex of heme, specifically ferric protoporphyrin IX with a chloride ligand. It forms when heme is oxidized in the presence of chloride ions and appears as a stable, soluble ferric porphyrin species in many solvents. The iron center is in the +3 oxidation state, while the porphyrin ring retains its conjugated system, giving characteristic spectroscopic properties.

Chemically, hematin can be prepared by oxidizing heme under chloride-rich conditions, or by treating heme with oxidizing agents such as hypochlorite. As a reagent, it serves as a model ferric heme compound for studies of heme chemistry, including ligand binding, redox behavior, and interactions with proteins or solvents. Hematin is distinct from hemozoin, the biogenic polymeric form produced by malaria parasites to detoxify free heme.

In biological contexts, hematin is not a common endogenous metabolite in healthy cells but can arise under oxidative stress or during experimental manipulation of heme. It has historically been encountered as a soluble form of ferric heme and has been used as a reference compound in spectroscopic analyses and in teaching about heme chemistry. Handling and disposal follow standard chemical safety practices for metalloporphyrin compounds, as hematin can be hazardous in certain forms and concentrations.