| Abstract
| - Product analysis of dealkylation in P(S)C(S)-soman-inhibited electric eel acetylcholinesterase(AChE) by GC−MS using the selected ion monitoring mode has been carried out. The instrument wascalibrated with pure standards of 2,3-dimethyl-1-butene and 2,3-dimethyl-2-butene in the gas phase andmethylene chloride extracts of 2,3-dimethyl-2-butanol and 3,3-dimethyl-2-butanol from the aqueous phase.The dealkylation in soman-inhibited AChE at pH 5.0 ± 0.2 and 25 °C produces close to 40% alkenes and50−60% 2,3-dimethyl-2-butanol. No 3,3-dimethyl-2-butanol could be detected to provide direct evidenceof the intervention of a secondary carbenium ion in the reaction path. All the products of the reactionoriginate from a tertiary carbenium ion. These findings are in good agreement with the results of Michelet al. [(1967) Arch. Biochem. Biophys. 121, 29], which were obtained by countercurrent distribution oftritium-labeled products and their identification by scintillation counting. The early experiments wereperformed with the mixture of the four soman diastereomers, all labeled with tritium in Cα.
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