Reactivation of Phosphorylated Acetylcholin-Esterase with Quaternary Pyridine Oximes Determination of Influencing Factors . Reaktivierung Phosphorylierter Acetylcholin-Esterase MIT Quaternierten Pyridin-Oximen Ermittlung Massgebender Faktoren

摘要

The systematic examination of factors influencing the reactivation of phosphorylated acetylcholin-esterase has shown that only oximes with K sub a values between 7.6 and 7.9 are effective (optimum at pK sub a approximately 7.8). Oximes with a pK sub a value less than 7.6 are useless as AChE-reactivators, because their anions are not sufficiently nucleophile, whereas aldoximes with a pK sub a greater than 7.9 are inactive, because their methin-protons are not sufficiently acid. Steric phenomena do not have a decisive influence. The second step of the reactivation is, under physiological conditions in the case of oximes with a pK sub a less than 7.9, an alpha, beta-cis-elimination of phosphoric acid from phosphorylated oximes and takes place as a cyclic mechanism. (Author)