Butyryl chloride

Solvents used were purchased from Fisher Scientific (https://www.fishersci.ca) or VWR International (https://ca.vwr.com). Acetylcholine iodide (AChI), acetylthiocholine iodide (ATChI), butyrylcholine iodide (BChI), butyrylthiocholine iodide (BTChI), purified recombinant human AChE, 3,3′- diaminobenzidine tetrahydrochloride (DAB), 1-methylpiperidin-4-ol, (S)-1-methylpyrrolidin-3-ol, (R)-1-methylpyrrolidin-3-ol, 4-iodobenzoyl chloride, 4-fluorobenzoyl chloride, acetyl chloride, butyryl chloride, iodomethane, 2-(dimethylamino)ethanethiol hydrochloride, potassium thioacetate, oxalic acid, gelatine, sodium azide, 1,5-Bis(4-allyldimethylammoniumphenyl)pentan-3-one-dibromide (BW 284c51), and deuterated solvents were purchased from Sigma-Aldrich (https://www.sigmaaldrich.com) or Oakwood Chemical (https://oakwoodchemical.com). BChE purified from human plasma was a gift from Dr. Oksana Lockridge (Eppley Institute, University of Nebraska Medical Centre, Omaha, Nebraska, United States). Gaseous argon (99.999% purity) was purchased from Air Liquide (https://www.airliquide.ca). Ortho-nitrofluoroacetanilide (o-NTFNAC) was synthesised as previously described⁵⁴ (link).

Lecitase™ Ultra (LU, >10 000 U × g⁻¹) was obtained from Sigma-Aldrich (St. Louis, MO, USA). Racemic alcohols: (E)-4-phenylbut-3-en-2-ol (1a), (E)-4-(4′-methylphenyl)but-3-en-2-ol (1b), (E)-4-(2′,5′-dimethylphenyl)but-3-en-2-ol (1c), and (E)-4-(4′-methoxyphenyl)but-3-en-2-ol (1d) were synthesized according to the procedures described earlier [61 ,62 (link),63 (link)]. Acetyl chloride (≥99%), propionyl chloride (98%), butyryl chloride (≥99%), sodium alginate, calcium chloride (≥96%), p-nitrophenyl palmitate (p-NPP), p-nitrophenol (p-NP), and polyethyleneimine (PEI) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Cyanogen bromide-activated agarose (Sepharose^® 4B) was purchased from GE Healthcare Bio-Sciences AB (Uppsala, Sweden). Supelite™ DAX-8 was purchased from Supelco Analytical (Bellefonte, PA, USA). sodium alginate was purchased from Sigma-Aldrich. Other chemicals were of analytical grade.