Phosphorus J‐coupling constants of ATP in human brain

Abstract

Proton decoupled 31P NMR spectroscopy of the occipital brain of healthy volunteers was performed with a 1.5 T whole-body imager. By use of two-dimensional chemical-shift imaging in combination with slice-selective excitation well resolved localized spectra (38 ml) were obtained within 34 min from which the homonuclear 31P-31P J-coupling constants of ATP could be determined: J(gammabeta) = 16.1 Hz +/- 0.2 Hz and J(alphabeta) = 16.3 Hz +/- 0.1 Hz (mean +/- SEM, n = 14). Both, the J-coupling constants and the chemical-shift difference between alpha- and beta-ATP (delta(alphabeta) = 8.61 ppm +/- 0.01 ppm) were used to calculate the concentration of intracellular free magnesium. The concentrations are 0.39 mM +/- 0.09 mM by using the average of both coupling constants of each spectrum, which is in fair agreement with 0.32 mM +/- 0.01 mM obtained from the chemical shift of alpha and beta phosphate resonances, which is the more accurate result.

Studies of polyphosphate composition and their interaction with dairy matrices by ion chromatography and 31P NMR spectroscopy

“…The J coupling constants measured on the PP1 multiplets ranged from 13 to 19 Hz. These results were in agreement with values determined in adenosine triphosphate from human brain (Jung et al, 1997). The signal at À21.44 ppm may be assigned to P3c (Lack, Dulong, Picton, Le Cerf, & Condamine, 2007).…”

Quantification ofin vivo31P NMR brain spectra using LCModel

“…All spectra were analyzed using LCModel version 6.3‐0G (Stephen Provencher, Oakville, ON, Canada) . Basis spectra were simulated using home‐written programs in MATLAB using published and measured 31 P chemical shifts and 31 P– 31 P J ‐coupling ( J PP ) and long‐range 31 P– 1 H J ‐coupling ( J PH ) constants (Table ). For the basis set generation, LCModel requires that each basis spectrum has a singlet peak for referencing, and by default LCModel uses the 0.0 ppm chemical shift.…”

31P-MR spectroscopy in children and adolescents with a familial risk of schizophrenia

“…A linear combination of a constant term A 0 and ten Fourier terms was used to correct the baseline of the truncated FID according to the following equation: (1) with ∆ν=ν max -ν, BW=ν max -ν min and ν min ≤ν≤ν max . Since J-coupling is not very weak compared with the chemical shift δ at 1.5 T (J α , β = 16.3 Hz, J γ , β =16.1 Hz and δ α , β =8.61 ppm) [18], deviations from exact binomial signal distributions are expected in the NTP multiplets. Amplitude, linewidth and resonance frequencies were varied, whereas the coupling constants and signal intensity ratios within the multiplets were kept constant.…”