REDOX POTENTIALS AND ACID-BASE EQUILIBRIA OF NADH/NAD+ ANALOGS IN ACETONITRILE

Redox potentials E°i of seven NADH/NAD+ analogues (acridine, phenanthridine, quinoline, and pyridine derivatives) have been determined in acetonitrile. The pKa's of the protonated forms of three reduced species AiH have also been determined together with the formation constants pKBx and pK OH of pseudobases resulting from the respective additions of amines and hydroxide to the seven oxidized forms Ai+. Structural assignments and quantitative conclusions are based on 1H NMR and UV-vis spectrometries. For derivatives of quinolinium or pyridinium ring systems, there exists a linear correlation between E°i and p/CioH with a slope of -29.6 mV. © 1990, American Chemical Society. All rights reserved.