ro 3-0422 ro 3-0422 ro 3-0422 is an extremely potent organophosphate acetylcholinesterase inhibitor. it is extremely toxic. the intravenous ld50 is 20 μg/kg in mice. it is over 300 times more potent than neostigmine. ro 3-0422 names preferred iupac name 3--1-methylquinolin-1-ium methyl sulfate other names 3-(diethoxyphosphinyloxy)-1-methylquinolinium methylsulfate identifiers cas number 5823-09-6 3d model (jsmol) interactive image chemspider 174347 pubchem cid 201356 comptox dashboard (epa) dtxsid80206962 smiles ccop(=o)(occ)oc1cc2ccccc2(c1)c.cos(=o)(=o) properties chemical formula c15h22no8ps molar mass 407.37 g·mol−1 hazards occupational safety and health (ohs/osh): main hazards extremely toxic lethal dose or concentration (ld, lc): ld50 (median dose) 20 μg/kg (mice, intravenous) except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). infobox references