METABOLISM OF ACARICIDE CHEMICAL, FENAZAFLOR (5,6-DICHLORO-1-PEHNOXYCARBONYL-2-TRIFLUOROMETHYLBENZIMIDAZOLE), AND RELATED 2-TRIFLUOROMETHYLBENZIMIDAZOLES IN CERTAIN MAMMALS, INSECTS, AND PLANTS

Mouse liver and mouse plasma hydrolyze fenazaflor (5,6-dichloro-1-phenoxycarbonyl-2-trifluoromethylbenzimidazole) to 5,6-dichloro-2-trifluoromethylbenzimidazole (5,6-Cl2-TFB). Microsomalmixedfunction oxidases of mouse liver hydroxylate the benzene moiety of 4,5-dichloro-2-trifluoromethylbenzimidazole (4,5-Cl2-TFB) and 5,6-Cl2-TFB. Rats or mice treated orally with fenazaflor or 5,6-Cl2- TFB excrete the following products in urine: 5,6-Cl2-TFB; 5,6-Cl2-TFB N-glucuronide (major product in mice); conjugates of 4-hydroxy-5,6-Cl2-TFB, 4,7-dihydroxy-5,6-Cl2-TFB, and 6-chloro-5-hydroxy-TFB (major products in rats). Certain conjugates chromatograph in the manner anticipated for riboside and glucoside derivatives. Urine of rats treated orally with 4,5-Cl2-TFB contains conjugates of 6-hydroxy-4,5-Cl2-TFB (major), 7-hydroxy-4,5-Cl2-TFB (minor), and 5-hydroxy-4,6-Cl2-TFB(minor). Houseflies excrete 4,5-Cl2-TFB and 5,6-Cl2-TFB as the N-glucoside and, possibly, the N-glucoside-hphosphate derivatives. Fenazaflor is more persistent than 5,6-Cl2-TFB on bean foliage but, in bean plants, each compound converts to products retained in the acetone-insoluble residue. Apple foliage and fruit treated with fenazaflor contain 5,6-Cl2-TFB, N- and O-conjugates of 4-hydroxy-5,6-Cl2TFB (possibly the glucosides), an unidentified trifluoromethylbenzimidazole occurring only on the surface, and unextractable derivatives formed from the absorbed material. © 1969, American Chemical Society. All rights reserved.