Physicochemical properties such as acid dissociation constant, pK(a), and lipophilicity, log P, of some bis-pyridinium monooximes with varying functionalities in the second pyridinium ring of the reactivator have been evaluated spectrophotometrically. In vitro reactivation kinetics of the investigated oximes against paraoxon inhibited electric eel AChE has been carried out.
The studied oximes have pK(a) values within the range of 7.85-8.38 and negative log P values, exhibiting their low lipophilic character. Further, on the basis of reactivation parameters (k(r), K-D, k(r2)) the efficacy of bis-pyridinium monooximes has been explained.