INVITRO METABOLISM OF DIAZINON AND ETRIMFOS BY CORN PLANT PREPARATIONS

Homogenates prepared from excised roots or stems and leaves of corn seedlings metabolize up to 72% of [14C]pyrimidinyl-labeled diazinon (O,O-diethyl-O-[6-methyl-2-(1-methylethyl)-4-pyrimidinyl]phosphorothioate) to 6-methyl-2-(1-methylethyl)-4-hydroxypyrimidine and one unidentified metabolite. Six-day-old corn seedling homogenate had the highest degradative activity. The optimum pH for activity was 6.0 and the activity was found to reside in the cytosol. Etrimfos [O,O-dimethyl-O-(6-ethyl-4-pyrimidinyl)phosphorothioate] was not susceptible to degradation by the corn plant preparation. © 1979.