Mannose (MN)

Mannose is a sugar monomer of the aldohexose series of carbohydrates. Mannose is not well metabolized in humans. 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 2C4 pucker in the solution ring form.