mannose

Mannose
Identifiers
CAS number	31103-86-3
PubChem	18950
MeSH	Mannose
Properties
Molecular formula	C6H12O6
Molar mass	180.156 g mol-1
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

D and L straight-chain forms of mannose drawn using Fischer projections.

Mannose is a sugar monomer of the aldohexose series of carbohydrates.

Metabolism

Mannose is not well metabolized in humans.^[1] Therefore, it does not significantly enter the carbohydrate metabolism when taken orally, and although traces of exogeneously introduced mannose have been detected in all body tissues, using radioactive markers, in a well hydrated mammal, although further studies are necessary, 90% of mannose ingested is excreted unconverted into the urine within 30 - 60 minutes, with 99% of the remainder being excreted within the following 8 hours. There is no significant increase in blood-glucose levels during this time.

Mannose is present in numerous glycoconjugates including N-linked glycosylation of proteins. C-mannosylation is also abundant and can be found in collage-like regions. Mannose is a C2 epimer of glucose and displays a ⁴C₁ pucker in the solution ring form.

Recombinant proteins produced in yeast may be subject to mannose addition in patterns different from those used by mammalian cells^[2]. This difference in recombinant proteins from those normally produced in mammalian organisms may influence the effectiveness of vaccines.

Formation

Mannose can be formed by the oxidation of mannitol.

It can also be formed from D-glucose in the Lobry-de Bruyn-van Ekenstein transformation

D-mannose is sold as a naturopathic remedy for urinary tract infections, and it is claimed to work through the disruption of adherence of bacteria in the urinary tract.

Etymology

The root of both "mannose" and "mannitol" is manna, which the Bible records as the food supplied to the Israelites during their journey through the Sinai Peninsula. Manna is a sweet secretion of several trees and shrubs, such as Fraxinus ornus.

Configuration

The fact that D-mannose has the same configuration at its penultimate carbon as D-glyceraldehyde is unsurprising as that is what defines the dextro classification. However, mannose differs from D-glucose by inversion of the C2 chiral center. This apparently simple change leads to the drastically different chemistry of the two hexoses, as it does the remaining six aldohexoses.

See also

• Glycosylation
• alpha-Mannosidase
• Hexose
• Mannose receptor

References

1. ^ Direct utilization of mannose for mammalian glycoprotein biosynthesis. Oxford Journals, Life Sciences, Glycobiology, Volume 8, Number 3 Pp. 285-295
2. ^ Vlahopoulos S, Gritzapis AD, Perez SA, Cacoullos N, Papamichail M, Baxevanis CN. Mannose addition by yeast Pichia Pastoris on recombinant HER-2 protein inhibits recognition by the monoclonal antibody herceptin. Vaccine. 2009 Jul 23;27(34):4704-8. Epub 2009 Jun 9.PMID: 19520203

External links