ANALYSIS OF MYOINOSITOL PHOSPHATES BY 2D H-1-NMR SPECTROSCOPY

2D 1H-N.m.r. spectroscopy applied to phosphorylated myo-inositols can indicate the number and the sites of phosphorylation, and up to three isomers can be completely analyzed simultaneously. The resonance of the sole equatorial proton (H-2) is shifted furthest downfield (to ∼4.7 p.p.m.) when C-2 is phosphorylated; when C-5 is unphosphorylated, the H-5 resonance has the lowest chemical shift (∼ 3.3 p.p.m.). The number of sites of phosphorylation can be determined from the sum of the chemical shifts for the resonances in a given myo-inositol phosphate and, based on the data presented, an algorithm can be constructed that will identify any myo-inositol phosphate on the basis of the chemical shifts. © 1990.