haematin
{{Short description|Chemical compound}}
{{distinguish|haematein}}
Haematin (also known as hematin, ferriheme, hematosin, hydroxyhemin, oxyheme, phenodin, or oxyhemochromogen) is a dark bluish or brownish pigment containing iron in the ferric state, obtained by the oxidation of haem.{{Cite journal|title = haematin. (n.d.) Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. (2003). Retrieved December 17 2015|url = http://medical-dictionary.thefreedictionary.com/haematin}}
Haematin inhibits the synthesis of porphyrin (by repressing ALAS1 synthesis),{{Cite book |last=Rodwell |first=Victor W. |title=Harper's Illustrated Biochemistry |publisher=McGraw-Hill Education |year=2018 |isbn=978-1-25-983794-4 |edition=31st |pages=311}} and stimulates the synthesis of globin. For this reason, it is used in the treatment of porphyrias.
It is a component of cytochromes and peroxidases. Haematin derived synthetically from hemin is used as a reagent.{{Cite journal|title = haematin. (n.d.) Dorland's Medical Dictionary for Health Consumers. (2007). Retrieved December 17 2015|url = http://medical-dictionary.thefreedictionary.com/haematin}}