Photophysical and Redox Properties of Dibucaine and Primaquine: A Comparison Study

Molecular modeling of the voltammetric oxidation at a glassy carbon electrode of the antimalarial drug primaquine and its prodrugs succinylprimaquine and maleylprimaquine

“…At pH 7.58 and scan rate (ν) of 0.1 V/s the oxidation wave is irreversible with anodic peak potential (E p,a ) = 0.654 V. The scan rate variation from 0.05 to 2.0 V/s causes increase in the height of the oxidation wave and E p,a is shifted towards positive potential. The relationship between anodic current values (I p,a ) and ν 1/2 is linear, indicating that the electrodic reaction was controlled by diffusion, confirming previous results [1][2][3].…”

“…Theoretical and experimental results indicated the existence of a relationship between the primaquine dissociation equilibrium and its electrooxidation process, and the quinoline ring displayed a fundamental role in both phenomena [1]. Moreover, the diprotonated form of primaquine was readily oxidized to a radical where the unpaired electron was delocalized over the 0013 aromatic ring [2][3][4] and, working in alkaline medium, a cation radical was obtained as an intermediate in primaquine oxidation [2].…”

“…The electrooxidation of primaquine diphosphate was studied by cyclic voltammetry using glassy carbon [1,2] and platinum [3] electrodes. The cyclic voltammogram of this drug showed only one irreversible anodic wave controlled by diffusion, involving two electrons in the rate-determining step of the electrode reaction [1].…”

Selective Effect of Procaine, Tetracaine and Dibucaine on Gold Nanoparticles

“…For procaine values of 8.8-9.0 (tertiary N) and respectively 2.0-2.3 (-NH 2 group) were reported. 24 25 27 In dibucaine the pK a for the aliphatic amine group is 8.5-10.2, and for the quinoline N about 2 [28][29][30] or 0.44. 25 For tetracaine, calculations using DFT (density functional theory) showed that protonation should occur primarily at the tertiary nitrogen atom; 31 its pK a value is 8.2-8.5; 25 32 for the other nitrogen atom, the pK a is about 2.1-2.3.…”

New procedure to synthesize silver nanoparticles and their interaction with local anesthetics

“…The two pK a values, for the two steps of dissociation from the dicationic form BH 2 2+ to the monocationic BH + , respectively, from this to the neutral form (B) are between 8.8 and 9 for the tertiary nitrogen in procaine, and between 2.0 and 2.3 for its −NH 2 group. 33,34,39 For the aliphatic amine group in dibucaine, pK a values between 8.5 and 10.2 were obtained, while for the quinoline, proposed N values were about 2 [40][41][42] or 0.44.…”