tmtfa tmtfa tmtfa is an extremely potent acetylcholinesterase inhibitor. as a transition state analog of acetylcholinesterase, tmtfa is able to inhibit acetylcholinesterase at extremely low concentrations (within the femtomolar range), making it one of the most potent acetylcholinesterase inhibitors known. tmtfa names preferred iupac name n,n,n-trimethyl-3-(trifluoroacetyl)anilinium identifiers cas number 156781-80-570311-60-3 (iodide salt) 3d model (jsmol) interactive image chemspider 5291 pubchem cid 5492 unii z3m6q7j3mz y comptox dashboard (epa) dtxsid20274468 inchi inchi=1s/c11h13f3no/c1-15(2,3)9-6-4-5-8(7-9)10(16)11(12,13)14/h4-7h,1-3h3/q+1key: jibzstpmdksjox-uhfffaoysa-n smiles c(c)(c)c1=cc=cc(=c1)c(=o)c(f)(f)f properties chemical formula c11h13f3no molar mass 232.226 g·mol−1 hazards lethal dose or concentration (ld, lc): ld50 (median dose) 1.6 mg/kg (intraperitoneal, mice) (as iodide salt) except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). infobox references mechanism of action tmtfa has a reactive ketone group that can covalently bind to the serine residue in the active site of acetylcholinesterase. this is due to the electron-withdrawing trifluoromethyl group on the carbonyl group.