6050-81-3

white powder

Acetylcholinesterase (AChE) enzyme plays an important physiological role in the neurotransmission process.

The chloride can be purified in the same way as the bromide, and it can be prepared from the iodide. A few milligrams dissolved in H2O can be purified by applying onto a Dowex-1 Cl-resin column (prepared by washing with N HCl followed by CO3 -free H2O until the pH is 5.8). After equilibration for 10minutes, elution is started with CO3 -free distilled H2O, and 3mL fractions are collected and their OD values at 229nm are measured. The fractions with appreciable absorption are pooled and lyophilised at 0-5o. Note that at higher temperatures decomposition of the ester is appreciable; hydrolysis is appreciable at pH >10.5/20o. The residue is dried in vacuo over P2O5, checked for traces of iodine (add conc H2SO4 and heat, violet vapours are released), and recrystallise it from propan-1-ol. [Gal & Roth Clin Chim Acta 2 316 1957, Beilstein 4 IV 1585.]