hemin

Hemin is an iron containing metalloporphyrin. Specifically, the Fe3+ oxidation product of heme is termed hemin. Hemin acts as a feed-back inhibitor on ALA synthase. Hemin also inhibits transport of ALA synthase from the cytosol (its' site of synthesis) into the mitochondria (its' site of action) as well as represses synthesis of the enzyme. Hemin is also known as a drug that is derived from processed red blood cells. Hemin for injection was known previously as hematin.