Ononitol
Iupacname4-O-methyl-myo-inositol
Systematicname(1R,2S,3S,4S,5S,6S)-6-Methoxycyclohexane-1,2,3,4,5-pentol

Ononitol is an organic compound with the formula (CHOH)5(CHOCH3). It is derivative of inositol, specifically 4-O-methyl-myo-inositol: an ether that can be described as the result of replacing the hydroxyl (–OH) in position 4 of myo-inositol by a methoxy group.

This compound occurs in several organisms.[1] It is one of the predominant soluble carbohydrate derivatives in the root nodules of the pea plant created by the bacterium Rhizobium leguminosarum,[2] and a constituent of Medicago sativa.[3]

Biosynthesis

The enzyme inositol 4-methyltransferase, which has been characterised from Mesembryanthemum crystallinum and Vigna umbellata, catalyses a methylation reaction in which inositol (myo-inositol) is converted to ononitol. The methyl group comes from the cofactor, S-adenosyl methionine (SAM).[4][5]

References

  1. ^ Singh, Madhulika; Kumar, Jitendra; Singh, Samiksha; Singh, Vijay Pratap; Prasad, Sheo Mohan (2015). "Roles of osmoprotectants in improving salinity and drought tolerance in plants: A review". Reviews in Environmental Science and Bio/Technology. 14 (3): 407–426. Bibcode:2015RESBT..14..407S. doi:10.1007/s11157-015-9372-8
  2. ^ Lief Skøt, Helge Egsgaard (1984): "Identification of ononitol and O-methyl-scyllo-inositol in pea root nodules". Planta, volume 161, pages 32–36. doi:10.1007/BF00951457
  3. ^ E. A. McComb and V. V. Rendig (1962). "Ononitol (4-O-methyl-myo-inositol) as a constituent of Medicago sativa". Archives of Biochemistry and Biophysics. 99 (1): 192–193. doi:10.1016/0003-9861(62)90261-8
  4. ^ Vernon DM, Bohnert HJ (1992). "A novel methyl transferase induced by osmotic stress in the facultative halophyte Mesembryanthemum crystallinum". EMBO J.. 11 (6): 2077–85. doi:10.1002/j.1460-2075.1992.tb05266.x. PMC 556674. PMID 1600940
  5. ^ Wanek W & Richter A (1995). "Purification and characterization of myo-inositol 6-O-methyltransferase from Vigna umbellata Ohwi et Ohashi". Planta. 197 (3): 427–434. Bibcode:1995Plant.197..427W. doi:10.1007/bf00196663