title: Tritium labeling of a powerful methylphosphonate inhibitor of cholinesterase: synthesis and biological applications.
abstract: 7-(Methylethoxy phosphinyloxy)-1-methyl-quinolinium iodide (MEPQ), a powerful anti-cholinesterase methylphosphonate ester, was labeled with tritium (9 Ci/mmol) at the methylphosphonyl moiety (TCH2P(O)(OR)X) by an iodine-tritium replacement reaction. Kinetic measurements of the rate of inhibition of acetylcholinesterase (AChE) by [3H]MEPQ and its rate of hydrolysis in alkaline solution confirmed the identity of [3H]MEPQ with authentic MEPQ, which was prepared by the same reaction sequences. Gel-filtration experiments verified the radiospecificity of [3H]MEPQ. In vitro radiolabeling of both AChE and butyrylcholinesterase along with the whole-body autoradiography of [3H]MEPQ-treated mice suggests that [3H]MEPQ is a convenient marker for studying biological systems containing these esterases.
authors: Israel Institute for Biological Research, Ness-Ziona.
authors: A
authors: A
authors: Balan
authors: I
authors: I
authors: Barness
authors: G
authors: G
authors: Simon
authors: D
authors: D
authors: Levy
authors: Y
authors: Y
authors: Ashani
mesh_terms: D000110:Acetylcholinesterase; D000818:Animals; D001345:Autoradiography; D002091:Butyrylcholinesterase; D002800:Cholinesterase Inhibitors; D002850:Chromatography, Gel; D007553:Isotope Labeling; D051379:Mice; D011806:Quinolinium Compounds; D014316:Tritium
chemical_list: D002800:Cholinesterase Inhibitors; D011806:Quinolinium Compounds; D014316:Tritium; C044294:7-((methylethoxyphosphinyl)oxy)-1-methylquinolinium; D000110:Acetylcholinesterase; D002091:Butyrylcholinesterase