1H NMR titrations of hydroxy protons in aqueous solution as a method of investigation of intramolecular hydrogen-bonding in phosphorylated compounds: examples of myo-inositol 2-phosphate and myo-inositol 1,2,6-tris(phosphates).
1H NMR hydroxy proton titration experiments for myo-inositol 2-phosphate and myo-inositol 1,2,6-tris(phosphates) in aqueous solution are presented to demonstrate that by following OH signals versus pH, evidence can be brought for HB interaction between the hydroxyl and phosphate groups. The chemical shifts of the OH protons vicinal to phosphate groups appear deshielded by ca. 2.5 ppm with regard to those two centers removed from the phosphates. Remarkably, the deshielded protons are only present when their neighboring phosphate groups are fully deprotonated but persist until high pHs. From these results, C-OH...2-O3P-O type I, C-HO...-HO3P-O type II and C-OH...-HO3P-O type III hydrogen bonds are evidenced and discussed.
Felemez
Marc
M
Laboratoire de Pharmacochimie de la Communication Cellulaire, UMR 7081 du CNRS, Université Louis Pasteur, Faculté de Pharmacie, 74 route du Rhin, 67401 Illkirch Cedex, France.
Spiess
Bernard
B
D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D007295:Inositol Phosphates / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D010766:Phosphorylation; D011522:Protons; D017186:Titrimetry
D007295:Inositol Phosphates; D011522:Protons; C047872:inositol 2-monophosphate; C059368:atrinositol