Metabolism of Ipconazole, a New Triazole Fungicide for Seed Treatment, in Rice Plants

The metabolism of ipconazole, (1RS, 2SR, 5RS; 1RS, 2SR, 5SR)-2-(4-chlorobenzyl)-5-isopropyl-1-(1H-1,2,4-triazol-1-ylmethyl)cyclopentanol, in rice seedlings and mature plants after seed treatment was investigated. Seeds were treated with two different types of 14 C-labeled ipconazole, [T- 14 C]-ipconazole labeled at the triazole ring and [B- 14 C]-ipconazole labeled at the benzylmethylene position. After 22 days of seeding, 40-41%of the applied radioactivity was recovered from soil, 27% from roots and seeds, and only 0.36-0.42% from rice shoots. The main metabolites of ipconazole in rice seedlings after seed treatment or root application were oxidative products at the carbons of the isopropyl group (methyl and methine) and the benzylmethvlene, although trace amounts of conjugated metabolites were observed. Seedlings from seeds treated with 14 C-ipconazole were cultivated for 144 days in Wagner pots, and radioactive residues in harvested grains were analyzed. Residues in hulled rice from the plants treated with [T- 14 C]-ipconazole and [B- 14 C]-ipconazole were 2.5 μg eq.lkg and 0.2 μg eq./kg, respectively. rpconazole and its metabolites detected in seedlings were not found in hulled rice, and most of the radioactivity derived from [T- 14 C]-ipconazole was detected in the unextractable residue and water soluble fraction from hulled rice