D-Ribose
IUPAC name	D-Ribose
Identifiers
CAS number	50-69-1 Y
PubChem	5779
EC-number	200-059-4
Properties[1][2]
Molecular formula	C5H10O5
Molar mass	150.13 g/mol
Appearance	white solid
Melting point	95 °C, 368 K, 203 °F
Solubility in water	very soluble
Chiral rotation [α]D	−21.5º (H2O)
Related compounds
Related aldopentoses	Arabinose Xylose Lyxose
Related compounds	Deoxyribose
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Ribose, primarily occurring as D-ribose, is an organic compound that occurs widely in nature. It is an aldopentose, that is a monosaccharide containing five carbon atoms that, in its acyclic form, has an aldehyde functional group at one end. This species predominantly exists in the cyclic form, as depicted in the upper right. It was first reported in 1891 by Emil Fischer. It comprises the backbone of RNA, a biopolymer that is the basis of genetic transcription. It is related to deoxyribose, as found in DNA, by the removal of one hydroxy group. Once phosphorylated, ribose can become a subunit of ATP, NADH, and several other compounds that are critical to metabolism.

The "D-" in the name D-ribose refers to the stereochemistry of the chiral carbon atom farthest away from the aldehyde group (C-4). In D-ribose, as in all D-sugars, this carbon atom has the same configuration as in D-glyceraldehyde. The enantiomer of D-ribose is L-ribose, which has a mirror image structure: L-ribose is not found in nature and has attracted little interest.

[edit] Phosphorylation

In biology, D-ribose must be phosphorylated by the cell before it can be used. Ribokinase catalyzes this reaction by converting D-ribose to D-ribose 5-phosphate. Once converted, D-ribose-5-phosphate is available for the manufacturing of the aminoacids tryptophan and histidine, or for use in the pentose phosphate pathway.

[edit] Use as a supplement

D-ribose is often marketed as a supplement for bodybuilders with a common recommended daily dose being 5 g, even though some studies have found no evidence there is a benefit, others have found increased endurance, recovery and muscle output in healthy individuals.^{[citation needed]}

D-ribose has also been used to reduce fatigue in fibromyalgia and chronic fatigue syndrome. A 2006 pilot study concluded that D-ribose (5 g three times a day) was effective in the treatment of FM and CFS.^[3] Although this study lacked any control group because essentially everyone involved was literally taking sugar pills, the authors reported that 66% of the 41 participants found the supplement helpful and it produced improvement in all the areas tested: energy, sleep, mental clarity, pain intensity, and well-being. Without further study, it is unclear if this is a substantial effect, or a placebo effect. In addition, there is no transporter or uptake mechanism for ribose in the intestine. The energy yield comes from two- and three-carbon compounds created when ribose is fermented by intestinal bacteria.^{[citation needed]}

[edit] References

[edit] External links

• D-Ribose on the website of China Greatvista Chemicals