Comparative metabolism of famoxadone in fish, plants and animals

✍ Scribed by Lee, Philip W; Lee, Dian Y; Brown, Alethia M; Jernberg, Kathryn M

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 156 KB
• Volume: 55
• Category: Article
• ISSN: 1526-498X
• DOI: 10.1002/(sici)1096-9063(199905)55:5<589::aid-ps959>3.0.co;2-5

✦ Synopsis

Fate in the soil environment

Famoxadone degrades rapidly in the soil under laboratory aerobic and anaerobic incubation conditions (DT 50 6 and 28 days, respectively), mainly by both hydrolytic and microbial action. [ 14 C] carbon dioxide and unextractable bound residues are recovered as primary terminal residues. The DT 50 of famoxadone in an aerobic aqueous sediment metabolism study is `1 day. The major degradation pathways include the hydroxylation of the parent molecule at the 4'-phenoxyphenyl position to yield compound 11 (Fig 4) and the hydrolytic cleavage of the oxazolidinedione-aminophenyl linkage to yield compounds 3, 4 and 5. A novel nitration reaction (at the 2-or 4-phenylamino position) in soil yields the nitro-analogs of famoxadone (12 and 13). The soil degradation rate is accelerated when famoxadone is exposed to simulated sunlight (DT 50 12 vs 28 days). The soil adsorption coef®cient of famoxadone (K oc ) is 3740. Aged soil column leaching studies show famoxadone and its soil metabolites to be compounds with low soil mobility potential. Signi®cant movement and persistence of famoxadone in the soil environment is not anticipated. The primary soil degradation pathway of famoxadone is presented in Fig 4.