Hexosamines

Glucosamine (C6H13NO5) is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine is part of the structure of two polysaccharides, chitosan and chitin. Glucosamine is one of the most abundant monosaccharides. It is produced commercially by the hydrolysis of shellfish exoskeletons or, less commonly, by fermentation of a grain such as corn or wheat. Glucosamine has various names depending on the country and its intended use.

thumb|N-Acetylglucosamine molecule '''N-Acetylglucosamine''' (GlcNAc) is an amide derivative of the monosaccharide glucose. It is a secondary amide between glucosamine and acetic acid. It is significant in several biological systems.

'''N-Acetylgalactosamine (GalNAc'''), is an amino sugar derivative of galactose.

Galactosamine is a hexosamine derived from galactose with the molecular formula C6H13NO5. This amino sugar is a constituent of some glycoprotein hormones such as follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

thumb|120px|right|Chemical structure of α-D-glucosamine. Note [[amine group (NH2).]] thumb|120px|right|Glucose. Note [[hydroxy group (OH) in place of the amine.]] Hexosamines are amino sugars created by adding an amine group to a hexose.

D-Mannosamine (2-amino-2-deoxymannose) is a hexosamine derivative of mannose.

Meglumine is a sugar alcohol derived from glucose that contains an amino group modification. It is often used as an excipient in pharmaceuticals and in conjunction with iodinated compounds in contrast media such as diatrizoate meglumine, iothalamate meglumine, and iodipamide meglumine.

'''N-Acetylmannosamine''' is a hexosamine monosaccharide. It is a neutral, stable naturally occurring compound. N-Acetylmannosamine is also known as N-Acetyl-D-mannosamine monohydrate, (which has the CAS Registry Number: 676347-48-1), N-Acetyl-D-mannosamine which can be abbreviated to ManNAc or, less commonly, NAM). ManNAc is the first committed biological precursor of N-acetylneuraminic acid (Neu5Ac, sialic acid) (Figure 1). Sialic acids are the negatively charged, terminal monosaccharides of carbohydrate chains that are attached to glycoproteins and glycolipids (glycans).

Perosamine (or GDP-perosamine) is a mannose-derived 4-aminodeoxysugar produced by some bacteria.

Bacillithiol (BSH or Cys-GlcN-mal) is a thiol compound found in Bacillus species. It is likely involved in maintaining cellular redox balance and plays a role in microbial resistance to the antibiotic fosfomycin.

Desosamine is a 3-(dimethylamino)-3,4,6-trideoxyhexose found in certain macrolide antibiotics (contain a high level of microbial resistance) such as the commonly prescribed erythromycin, azithromycin, clarithromycin, methymycin, narbomycin, oleandomycin, picromycin and roxithromycin. As the name suggests, these macrolide antibiotics contain a macrolide or lactone ring and they are attached to the ring desosamine which is crucial for bactericidal activity. The biological action of the desosamine-based macrolide antibiotics is to inhibit the bacterial ribosomal protein synthesis. These antibioti

Daunosamine is a deoxy sugar and amino sugar of the hexosamine class.

Fructosamines are compounds that result from glycation reactions between glucose and a primary amine, followed by isomerization via the Amadori rearrangement. Biologically, fructosamines are recognized by fructosamine-3-kinase, which may trigger the degradation of advanced glycation end-products (though the true clinical significance of this pathway is unclear). Fructosamine can also refer to the specific compound 1-amino-1-deoxy-D-fructose (isoglucosamine), first synthesized by Nobel laureate Hermann Emil Fischer in 1886.

Bacillosamine is a rare amino sugar first discovered in Bacillus subtilis.

Aspartylglucosamine is a derivative of aspartic acid.