NMR Spectroscopy, 31P

The Ad‐MD method to calculate NMR shift including effects due to conformational dynamics: The 31P NMR shift in DNA

“…The effect of the external reference on theoretical δ 31P values is demonstrated for the 31 P NMR experiments, in DNA referenced to the trimethyl phosphate (TMP) 64 and phosphoric acid (H 3 PO 4 ). 22 The difference of measured δ 31P values relative to TMP and H 3 PO 4 ranges from À3.26 to À3.12 ppm, (À3.19 ppm on average, Table S12). Theoretical δ 31P referenced to TMP and H 3 PO 4 differ by À2.86 ppm (Table S12).…”

“…[18][19][20][21] In particular, flipping of ζ from gauche(À) (g À ) to trans (t) orientation (while keeping the α in g À ) translated to 1.6 ppm change in δ 31P . 22 The orientations of ζ (along with ε) are characteristic of two distinct backbone geometries referred to as BI-DNA (ε/ζ = t/g À ) and BII-DNA (ε/ζ = g À /t), 23,24 and magnitudes of δ 31P in DNA can be assigned accordingly. 22,25,26 It is noteworthy that in DNA δ 31P vary only little, usually less than mentioned above, owing to structural similarity of phosphates.…”

Magnetic Resonance pH Imaging in Stroke – Combining the Old With the New

“…Magnetic resonance spectroscopy (MRS) is a non-invasive technique that allows for the measurement of different metabolic or neurochemical profiles of the brain via the spectra of atomic nuclei such as 1 H, 13 C, 19 F, 23 Na, or 31 P (Cichocka et al, 2015). Historically 31 P MRS, whose signal originates from inorganic phosphate (Pi), adenosine triphosphate, adenosine diphosphate, phosphocreatine (PCr), and sugar phosphates (Gorenstein and Luxon, 2017), has long been regarded as the gold standard for the measurement of intracellular pH. However, many aspects of 31 P spectroscopy still limit the use of the technique in the clinical setting, mostly arising from relatively poor spatial and temporal resolution, as well as the need for high field strengths and specialized receiver coils.…”