Anomeric Effect in Phosphate Moieties of Carbohydrates: An ab initio Study

Kaliannan, P and Vishveshwara, S and Rao, VSR (1985) Anomeric Effect in Phosphate Moieties of Carbohydrates: An ab initio Study. In: International Journal of Quantum Chemistry, 27 (2). 181 -194.

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Abstract

Ab initio SCF MO calculations at the STO-3G level have been carried out on $CH_2OHOPO_3^-H$ and $CH_2OHOPO_3^{2-}$, which have been considered as model systems for the C1-phosphate moiety of sugars. The results predict higher anomeric energy for the phosphate moiety at C1 atom of pyranosides. Also a trans arrangement of the exocyclic 0-P bond is preferred rather than a gauche arrangement, thus exhibiting a reverse exo-anomeric effect. A complete potential energy map has been constructed for $CH_3OP_3^-H$, a model system for C6-phosphate moiety. It is seen that the bond angle optimization brings down the relative energies of various conformations. The effect of the phosphate group on the preferred conformation of phosphate containing polysaccharides is also discussed.

Item Type:	Journal Article
Publication:	International Journal of Quantum Chemistry
Publisher:	John Wiley & Sons
Additional Information:	Copyright of this article belongs to John Wiley & Sons.
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	12 Apr 2008
Last Modified:	19 Sep 2010 04:44
URI:	http://eprints.iisc.ac.in/id/eprint/13732

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