Outline
Glucosamine, also known as 2deoxy aminosamidose, is a common amino sugar and is a derivative of glucose. It is a compound formed by the substitution of hydroxyl on the second carbon atom of glucose molecule. A hydrogen atom on the amino group is often substituted by acetyl group to form N-acetylglucosamine. It rarely exists in organisms, mainly as chitin, glycoprotein and proteoglycan components.
Physicochemical properties
Its molecular formula is C6H13NO5, and its molecular weight is 179.17. Glucosamine has the property of polyhydroxylamines and exists in the cell walls of crustaceans, insects, molds and bacteria in the form of polymers or derivatives. Chitin (Nacetyl glucosamine condensate) produces amino glucosamine in water. The alpha body is crystalline and its melting point is 88 degrees, and it changes []D20100] to 47.5 degrees (30 minutes) in aqueous solution. The beta body can be obtained from methanol by acicular crystals, decomposing at 110 degrees, and changing in aqueous solution [alpha]D2028 degrees to 47.5 degrees (30 minutes). It is soluble in water, soluble in hot methanol, slightly soluble in cold methanol and ethanol, and insoluble in ethyl ether and chloroform. It exists in crustacean, mucin and mucin.
It is a trace organic component in seawater, particulates and marine sediments. The content of marine samples can be separated by hydrolysis and cation exchange column and determined by spectrophotometry.
Preparative method:dehydrated glucose and ammonia react in absolute ethanol, and then hydrolyze to produce crude glucosamine.
Natural Substance
Glucosamine hydrochloride is a natural substance that stimulates the body to make glycosaminoglycans to repair and form cartilage. Hydrochloride is a kind of easily absorbed small component, composed of amino acids such as glucose and glutamine.
Its function is to stimulate the production of synovial fluid and promote articular cartilage repair. It also strengthens the synthesis of connective tissue. Hydrochloride is a hydrophilic molecule that absorbs water into cartilage and improves cartilage elasticity. Glucosamine is an amino acid naturally occurring in the human body. Its role is to form and repair cartilage. Although glucosamine is a natural substance produced by human body, its level decreases with aging, resulting in cartilage degeneration.
Taking glucosamine as a nutritional supplement is one of the ways to help reduce the level of glucosamine in the body. Glucosamine nutritional supplement is the shell of crustacean seafood extracted from crabs, lobsters and shrimps. Crustacean seafood, like humans, naturally produces this substance. It is known that glucosamine nutritional supplements are effective for osteoarthritis. This is because glucosamine is the precursor of glycosaminoglycan, and the latter is the basic material for articular cartilage to repair cartilage tissue. The human body needs these glycosaminoglycans to make proteoglycans.
Proteoglycan is a substance similar to clay made from protein and sugar. Before collagen is deposited in the joint, it is the basic material for cartilage. The more glycosaminoglycan in articular cartilage, the higher the rate of cartilage formation. As glucosamine is the precursor of glycosaminoglycan, glucosamine supplements help to reduce inflammation and swelling of the joints and rebuild damaged cartilage, which is beneficial to the treatment of osteoarthritis. Previous studies have shown that patients with mild to moderate osteoarthritis can feel pain relieved after taking glucosamine. Its analgesic effect is similar to aspirin and Bloven (Ibuprofen) and other non steroidal anti-inflammatory drugs (NSAIDs). Other studies have shown that glucosamine may help slow down cartilage damage in osteoarthritis patients.
Application
It is widely used in the fields of health medicine, health food, cosmetics and other fields. It plays an important role in improving the life rate of human activities and promoting the growth of human synthetic life substance.
Chemical Properties
(β form.) Colorless needles. Mp 110C
(decomposes). Very soluble in water; slightly soluble
in methanol and ethanol; insoluble in ether and
chloroform.
Occurrence
Glucosamine is found in mucopolysaccharides, chitin, and mucoproteins. Glucosamine is a naturally occurring substance; glucosamine sulfate is manufactured synthetically.
Uses
Glucosamine is an amino sugar that can regulate growth factor gene transcription. It is also widely touted as remedy for osteoarthritis (OA).
Definition
ChEBI: The open-chain form of D-glucosamine.
brand name
Adaxil;Antatril;Arthryl;Chitosamine;Corti-anartril;Dona 200-s;Dona compositum;Donna 200;Pona;Terramycin;Terrastatom;Tetracyn;Thiocondramine;Viartril.
World Health Organization (WHO)
Glucosamine is found in chitin, mucoproteins and
mucopolysaccharides. It is used as a pharmaceutical aid. Glucosamine sulfate has
been used in the treatment of rheumatic disorders though it is not widely marketed for this purpose.
Veterinary Drugs and Treatments
These compounds may be useful in treating osteoarthritis or other
painful conditions in domestic animals, but large, well-designed
controlled clinical studies proving efficacy were not located. One
study in dogs (McCarthy, O’Donovan et al. 2007) showed some positive
effect, but this study was not placebo controlled and compared
responses versus carprofen. Another placebo-controlled, blinded
study in dogs (Moreau, Dupuis et al. 2003), did not demonstrate
statistically significant improvement after 60 days of treatment.
These compounds potentially could be of benefit in cats with
FLUTD (feline lower urinary tract disease) because of the presence
of glycosaminoglycans as part of the protective layer of the urinary
tract. Controlled studies have shown some positive effects in some
cats, but overall did not appear to make a significant difference.
Purification Methods
Crystallise the amines from MeOH. The free base has been obtained from the hydrochloride (21.5g, see below) in a mixture of Et3N (15mL) and EtOH (125mL) by shaking for 2days at room temperature, and the solid Et3N.HCl is filtered off and the process repeated with more Et3N (3-4 times) until the D-glucosamine (15g) is free from Cl ions. It has m 88o , [] D20 +100o mutarotating to +47.5o (c 1, H2O). When Et2NH is used as base, the to conversion is complete giving D-glucosamine. The pentaacetate is purified by dissolving in CHCl3, treating with charcoal, drying (MgSO4), evaporating the solvent, and adding a little dry Et2O to induce crystallisation. It has m 124-126o, [] D +113o (c 1, CHCl3) after 16hours in a desiccator. [Leaback Biochemical Preparations 10 118 1963.] The N-acetyl derivative, m 203-205o from MeOH/Et2O (dry in vacuum P2O5) has [] D +75o to +41o (c 2, H2O); this derivative can also be purified by dissolving in the minimum volume of H2O to which is added 7-8volumes of EtOH followed by Et2O until turbid and keeping at ~20o to crystallise. Wash the crystals with MeOH then Et2O and dry in vacuo over P2O5. [Horton Biochemical Preparations 11 1 1966.]
