Description
Produced from red blood cells, Hematin is a bluish-black or brownish pigment compound derived from hemoglobin by removal of the protein part and oxidation of the iron atom from ferrous Fe2+ to the ferric Fe3+ state, which does not combine with oxygen. It is effective to inhibit the synthesis of porphyrin and, at the same time, stimulate the synthesis of globin. It involves in the formation of cytochromes and peroxidases in the cell. Hematin is also a pharmaceutical used in the treatment of porphyria, which can be administered intravenously to halt the attack of acute porphyria. It functions in the liver to accelerate the production of heme and thus preventing the further accumulation of heme precursors, porphyrins, which is effective to alleviate the symptoms of porphyria.
References
https://en.wikipedia.org/wiki/Haematin
http://house.wikia.com/wiki/Hematin
https://en.oxforddictionaries.com/definition/us/hematin
http://medical-dictionary.thefreedictionary.com/hematin
Chemical Properties
Dark crystals with metalic luster
Uses
Hematin was used in a study to test
in vitro activities of the Rx-01 oxazolidinones against hospital and community pathogens.
It was also used in a study to test
in-vitro bacterial identification using fluorescence spectroscopy with an optical fiber system.
Uses
Indicator, biological stain.
Definition
The hydroxide of heme. Not to be confused with
hematein.
Biological Activity
Hematin is a hydroxide of heme. It may be used to tre at acute porphyric attacks. Hematin suppresses the hepatic aminolevulinic acid (ALA) function and replenishes cytochrome action by restoring the endogenous heme deficit. Early administration of hematin can prevent irreversible neuronal damage induced due to metabolic disorders.
Synthesis
Heme synthesis involves a seven-step enzymatic pathway, commencing with the condensation of glycine and succinyl-CoA to form δ-aminolevulinic acid (ALA). Subsequently, ALA is converted into porphyrinogen (PBG), which is further transformed into porphyrin IX. Ultimately, porphyrin IX binds with iron to form haem. The initial steps of this process occur within the mitochondria, whilst subsequent reactions take place in the cytoplasm. The specific steps are as follows:
(1) Condensation of Glycine and Succinyl-CoA (Enzyme: ALA synthase)
Reaction: Glycine + Succinyl-CoA → δ-aminolevulinic acid (ALA)
(2) Formation of Porphobilinogen (PBG) (Enzyme: ALA dehydratase)
Reaction: 2 ALA → PBG + 2 H2O
(3) Conversion of Porphobilinogen to Uroporphyrinogen III (Enzyme: Porphobilinogen deaminase)
Reaction: 4 PBG → Hydroxymethylbilane + 3 H2O
(4) Decarboxylation of Uroporphyrinogen III (Enzyme: Uroporphyrinogen decarboxylase)
Reaction: Hydroxymethylbilane → Uroporphyrinogen III + CO2 + H2O
(5) Oxidative Decarboxylation of Coproporphyrinogen III (Enzyme: Coproporphyrinogen oxidase)
Reaction: Coproporphyrinogen III → Protoporphyrinogen IX + CO2 + 2H2O
(6) Conversion of Protoporphyrinogen IX to Protoporphyrin IX (Enzyme: Protoporphyrinogen oxidase)
Reaction: Protoporphyrinogen IX → Protoporphyrin IX + H2O
(7) Insertion of Iron into Protoporphyrin IX (Enzyme: Ferrochelatase)
Reaction: Protoporphyrin IX + Fe2+ → Heme
Purification Methods
Crystallise it from pyridine. Dry it at 40o in vacuo.[Beilstein 26 III/IV 3047.]
