EFFECTS OF THE HERBICIDE SAFENER CGA-92194 ON THE CHEMICAL REACTIVITY OF METOLACHLOR WITH GLUTATHIONE AND ITS METABOLISM BY GRAIN SORGHUM SEEDLINGS

摘要

The effect of the safener CGA-92194 {α-[(1,3-dioxolan-2-yl-methoxy)imino] benzeneacetonitrile} on the chemical reactivity of the herbicide metolachlor [2-chloro-N-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] with glutathione (GSH) was examined in vitro under laboratory conditions. The formation of dual labeled GS-metolachlor was studied in a nonenzymatic reaction of ~3H-labeled GSH [L-(glycine-2-~3H)glutathione, sp. act. 1300 mCi/mmol] with ~(14)C-metolachlor (sp. act. 21.5 mCi/mmol) in a phosphate buffer (pH 7.0) under a nitrogen atmosphere and following an incubation of 3 h. The safener was used at 0, 1, 50, and 100 gM and increased the reactivity of metolachlor with GSH in a concentration-dependent pattern. A second reaction product of metolachlor with GSH also was detected but not positively identified. It appeared to be a catabolite of the GS-metolachlor conjugate.