Complexes of aluminium(III) with glucose-6-phosphate in aqueous solutions

NMR Spectra and Potentiometry Studies of Aluminum(III) Binding with Coenzyme NAD+ in Acidic Aqueous Solutions

“…These results are also in agreement with those of similar complexes, 8,11,12,17 and the situation generally observed for the octahedral complexes of Al, the chemical shifts of which mainly depend on the number of ligands around the cation. 19 Furthermore, the following potentiometry of the Al-NAD + system also substantiates these assignments.…”

“…The 13 C-NMR spectra of NAD + and Al-NAD + in the same concentration of acidic solutions (0.02 M NAD + , Al/NAD + = 1:2, pH = 3) did not show any obvious changes for the signals of nicotiamide and ribose rings after complexation, suggesting that Al did not promote, in this pH case, deprotonation of the sugar ring hydroxylic functions. 11 It can be seen in Figs. 3A and B that some shifted and broadened signals appeared in the complex spectrum.…”

“…terminal organic diphosphates (pKa = 5 -6). 11,12,16 Moreover, three species existed in the pH 4.0 aqueous solution, which are attributed to the AlLH 2+ , AlL2 -and Al2L2 2+ complexes. These results were proved by the above-mentioned multinuclear NMR spectra, especially in 27 Al-NMR spectroscopy.…”

“…7 It is well known that Al has a great affinity to phosphate oxygen. The interactions of Al with inorganic phosphate, 8 organophosphates (AMP, ADP, ATP), 9,16 phosphorylated amino acids 10 and gluose-6-phosphate 11 have been well investigated. In the past, the crystalline state of an extended conformation of NAD + was found with Li(I) coordinated to pyrophosphate oxygen and adenine N7′.…”

Complexation of Al(III) with reduced glutathione in acidic aqueous solutions

“…All glassware was soaked in 10% HNO 3 for at least 24 h, and then washed carefully with double-distilled water. The pH values in D 2 O solutions were corrected for the deuterium isotope effect by adding 0.45 to the meter reading[32].…”