Description
2-AMINOETHANETHIOL is the chemical compound with the formula HSCH2CH2NH2. It is the simplest stable aminothiol and a degradation product of the amino acid cysteine. It is often used as the hydrochloride salt, HSCH2CH2NH3Cl. The comparatively high melting point of cysteamine (95-97 °C), indicates that exists in a salt form.
Chemical Properties
2-AMINOETHANETHIOL is white powder
Uses
Scavenges benzyl and allyl halides and ketones.
Uses
antihyperlipidemic, HMGCoA reductase inhibitor
Definition
2-AMINOETHANETHIOL is an amine that consists of an ethane skeleton substituted with a thiol group at C-1 and an amino group at C-2.
Preparation
Cysteamine can also be prepared by the reaction of ethylenimine with hydrogen sulfide.
(NHCH2CH2) + H2S → HSCH2CH2NH2.
Reactions
2-AMINOETHANETHIOL is used as the hydrochloride salt, as it readily oxidizes to the corresponding disulfide, in the presence of air. The amine portion of the molecule serves as a catalyst for this reaction.
4 HSCH2CH2NH2 + O2 → 2 NH2CH2CH2SSCH2CH2NH2 + 2 H2O.
Pharmaceutical Applications
Under the trade name Cystagon, cysteamine is used in the treatment of disorders of cystine excretion. Cysteamine cleaves the disulfide bond with cystine to produce molecules that can escape the metabolic defect in cystinosis and cystinuria.
It is also used for treatment of radiation sickness.
Cysteamine is used in the body to form the essential biochemical coenzyme A by combining with pantothenate and adenosine triphosphate.
In 2008, Raptor Pharmaceuticals started phase II clinical trials testing a delayed release (DR) preparation of cysteamine bitartrate for Huntington's disease. DR Cysteamine is also being investigated as a treatment for cystinosis, Batten disease, and non-alcoholic steatohepatitis.
Biochem/physiol Actions
Cysteamine (β-mercaptoethylamine) depletes cystine from patient′s cells and there by regulates renal glomerular function and increases growth in them. Therefore, cysteamine is considered to be a potential therapeutic for nephropathic cystinosis.
Purification Methods
It is soluble in H2O giving an alkaline reaction, and it has a disagreeable odour. A likely impurity is the disulfide cystamine which is not soluble in alkaline solution. Under a N2 atmosphere dissolve it in EtOH, evaporate to dryness and wash the white residue with dry pet ether, then sublime it at 0.1mm and store it under N2 at 0-10o in the dark. Its HgCl2 (2:3) complex has m 181-182o (from H2O), and its picrate has m 125-126o. [Mills & Bogert J Am Chem Soc 57 2328 1935, 62 1173 1940, Baddiley & Thain J Chem Soc 800 1952, Shirley Preparation of Organic Intermediates (J. Wiley) Vol 3 189 1951, Barkowski & Hedberg J Am Chem Soc 109 6989 1987, Beilstein 4 IV 1570.]
