Arabinose

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Arabinose
DL-Arabinose.svg
Identifiers
CAS number 147-81-9 YesY, 10323-20-3 (D) YesY, 5328-37-0 (L) YesY
PubChem 5460291
ChemSpider 59687 YesY
EC-number 205-699-8
ChEBI CHEBI:46983 YesY
Jmol-3D images Image 1
Image 2
Properties[1]
Molecular formula C5H10O5
Molar mass 150.13 g mol−1
Appearance Colorless crystals as prisms or needles
Density 1.585 g/cm3 (20 ºC)
Melting point 164 to 165 °C (327 to 329 °F; 437 to 438 K)
Solubility in water Soluble
Hazards
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oil Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Related compounds
Related aldopentoses Ribose
Xylose
Lyxose
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
Infobox references

Arabinose is an aldopentose – a monosaccharide containing five carbon atoms, and including an aldehyde (CHO) functional group.

For biosynthetic reasons, most saccharides are almost always more abundant in nature as the "D"-form, or structurally analogous to D-glyceraldehyde.[note 1] However, L-arabinose is in fact more common than D-arabinose in nature and is found in nature as a component of biopolymers such as hemicellulose and pectin.

The L-arabinose operon, also known as the araBAD operon, has been the subject of much biomolecular research. The operon directs the catabolism of arabinose in E. coli, and it is dynamically activated in the presence of arabinose and the absence of glucose.[2]

A classic method for the organic synthesis of arabinose from glucose is the Wohl degradation.[3]

D-Arabinose
Alpha-D-Arabinofuranose.svg
α-D-Arabinofuranose
Beta-D-Arabinofuranose.svg
β-D-Arabinofuranose
Alpha-D-Arabinopyranose.svg
α-D-Arabinopyranose
Beta-D-Arabinopyranose.svg
β-D-Arabinopyranose

Etymology[edit]

Arabinose gets its name from gum arabic, from which it was first isolated.[4]

Use[edit]

In synthetic biology, arabinose is often used as a one-way or reversible switch for protein expression under the Pbad promoter in E. coli. This on-switch can be negated by the presence of glucose or reversed off by the addition of glucose in the culture medium which is a form of catabolite repression.[5]

Notes[edit]

  1. ^ For sugars, the D/L nomenclature does not refer to the molecule's optical rotation properties but to its structural analogy to glyceraldehyde.

References[edit]

  1. ^ Weast, Robert C., ed. (1981). CRC Handbook of Chemistry and Physics (62nd ed.). Boca Raton, FL: CRC Press. p. C-110. ISBN 0-8493-0462-8. 
  2. ^ Watson, James (2003). Molecular Biology of the Gene. p. 503. 
  3. ^ Braun, Géza (1940), D-Arabinose, Org. Synth. 20: 14 ; Coll. Vol. 3: 101 
  4. ^ Merriam Webster Dictionary
  5. ^ Guzman LM, Belin D, Carson MJ, Beckwith J. Tight regulation, modulation, and high-level expression by vectors containing the arabinose PBAD promoter. J Bacteriol. 1995 Jul;177(14):4121-30