Mannose
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Mannose is a sugar monomer of the hexose series of carbohydrates. Mannose enters the carbohydrate metabolism stream by phosphorylation and conversion to fructose-6-phosphate.
Mannose can be formed by the oxidation of mannitol. The root of both these words 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.
D-Mannose, which appears in some fruits including cranberry, has been shown to prevent the adhesion of bacteria to tissues of the urinary tract and bladder. However, the amount and concentration of the cranberry juice, as well as the duration of juice consumption needed to prevent urinary tract infections is uncertain. At best, cranberry juice can be considered to be minimally effective, but more scientific data need to be acquired.[1].
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 centre. This apparently simple change leads to the drastically different chemistry of the two hexoses, as it does the remaining six hexoses. The hexoses can be remembered conveniently by All (aldose) altruists (altrose) gladly (glucose) make (mannose) gum (gulose) in (idose) gallon (galactose) tanks (tallose).
[edit] See also
- Glycosylation
- alpha-Mannosidase
- Hexose
- The formation of mannose from D-glucose in the Lobry-de Bruyn-van Ekenstein transformation
[edit] References
- ^ Schaeffer, Anthony J. M.D. "Cranberry Juice and Urinary Tract Infection." The Journal of Urology. Volume 173(1), January 2005, pp 111-112. Accession Number: 00005392-200501000-00038
