Spatial structure, thermodynamics and kinetics of formation of hydrazones derived from pyridoxal 5′-phosphate and 2-furoic, thiophene-2-carboxylic hydrazides in solution

Dephosphorylation of pyridoxal 5′‐phosphate‐derived Schiff bases in the presence of bovine alkaline phosphatase

“…However, the loss of 31 P NMR signal quality was much less as phosphate remains dissolved. 31 P NMR chemical shifts obtained for hydrazones are in good agreement with the previously reported data: 3.85 ppm for PLP-F2H (3.83 ppm), 28 3.68 ppm for PLP-T2H (3.69 ppm), 28 3.80 ppm for PLP-3NH (3.76 ppm) 10 and 3.77 ppm for PLP-PRZ (3.79 ppm). 29 At pH 10, phosphate exists in the solution as HPO 4 2predominantly.…”

“…4-Nitrophenol (4NP) of unknown origin was twice recrystallized from ethanol and dried on air. Hydrazones were synthesized from PLP and corresponding hydrazides as described: PLP-3NH, 10 PLP-F2H, PLP-T2H, 28 and PLP-PRZ. 29 The impurities' absence was controlled using 1 H NMR spectroscopy.…”

High-pressure NMR spectroscopy in studies of the conformational composition of small molecules in supercritical carbon dioxide

“…We estimate the standard deviation of finding rexp as ±3%, which agrees to previous reports describing the NOESY analysis [65,68]. Thus, the inaccuracy of finding the conformer populations can be calculated, as it was made for small molecules in [42]. Based on the NOESY data with corresponding errors, the conformers fractions for ibuprofen are 48 and 52% ( Figure 6) with the accuracy of ±3%.…”

“…An alternative method is the NMR spectroscopy at high pressures, which has shown its usefulness in studies of molecular structure [24][25][26], host-guest interactions [27], metalorganic framework [28,29], ionic liquids [30][31][32], aqueous geochemistry [33][34][35][36] and operando studies of complex mixtures [37]. In addition, liquid state NMR spectroscopy is useful in studies of conformational exchange [38][39][40][41][42]. However, conducting NMR experiments under supercritical conditions requires a specialized high-pressure supercritical cell.…”

Multiple Reversible Dynamics of Pyrimidine Based Acylhydrazones

“…As well as the information of hydrazones structure in the solution might also be valuable since isometry and equilibria also affect the biochemical properties of compounds. [31] DFT calculations have previously been used to provide accurate predictions of the energy barrier in different organic molecules. [11,32,28] The optimized geometry parameters of conformer 2 and 3 at the B3LYP/6-311++G level of computation and the implicit solvent model to simulate CHCl 3 are listed in Tables S1-S4 from the supporting information.…”