Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture, Zhejiang University, Hangzhou 310029, China.
Sci Total Environ. 2010 Apr 15;408(10):2239-44. doi: 10.1016/j.scitotenv.2010.02.006. Epub 2010 Mar 1.
A soil metabolism study of propyl 4-(2-(4,6-dimethoxypyrimidin-2-yloxy)benzylamino)benzoate (ZJ0273), a novel broad-spectrum herbicide, was carried out using (14)C labeled on two different rings, i.e., [pyrimidine-4,6-(14)C] ZJ0273 and [benzyl-U-(14)C] ZJ0273. Ultralow liquid scintillation counting and LC-MS/MS were used to identify the degradation intermediates and quantify their dynamics in aerobic soils. Four aromatic intermediates, 4-(2-(4,6-dimethoxypyrimidin-2-yloxy)benzylamino)benzoic acid (M1), 4-(2-(4,6-dimethoxypyrimidin-2-yloxy)benzamido)benzoic acid (M2), 2-(4,6-dimethoxypyrimidin-2-yloxy)benzoic acid (M3), and 4,6-dimethoxypyrimidin-2-ol (M4), were identified and their identity was further confirmed against authentic standards. Analysis of metabolites suggested two degradation pathways: (1) Upon loss of the propyl group, M1 was produced via hydrolysis of propyl 4-(2-(4,6-dimethoxypyrimidin-2-yloxy)benzylamino)benzoate after which the C-N bond between rings A and B was cleaved by oxidation and biochemical degradation to yield M3, which was further converted into M4 and finally mineralized to CO(2); and (2) the first step was the same as in pathway 1, but M1 first underwent a carbonylation to form M2. The C-N bond between rings A and B of M2 was cleaved by hydrolysis to yield M3. Dynamic changes in the four metabolites in aerobic soils were also investigated by HPLC coupled analysis of radioactivity of isolated peaks. After a 100-day incubation, 1.7-9.7% of applied (14)C was found as M1, 0.3-1.1% as M2, 14.5-20.9% as M3, and 3.7-6.7% as M4 in the soils, and pH appeared to be the most influential soil property affecting the formation and dissipation of these metabolites.
采用两种不同的环上标记的 [嘧啶-4,6-(14)C]ZJ0273 和 [苄基-U-(14)C]ZJ0273 对丙基 4-(2-(4,6-二甲氧基嘧啶-2-基)苯甲氨基)苯甲酸酯（ZJ0273，一种新型广谱除草剂）进行了土壤代谢研究。超低位液体闪烁计数和 LC-MS/MS 用于鉴定降解中间体，并定量分析好氧土壤中它们的动态变化。鉴定出了 4 种芳族中间体，4-(2-(4,6-二甲氧基嘧啶-2-基)苯甲氨基)苯甲酸（M1）、4-(2-(4,6-二甲氧基嘧啶-2-基)苯甲酰胺基)苯甲酸（M2）、2-(4,6-二甲氧基嘧啶-2-基)苯甲酸（M3）和 4,6-二甲氧基嘧啶-2-醇（M4），并通过与对照标准品的比较进一步确认了它们的身份。代谢物分析表明存在两种降解途径：（1）在失去丙基后，M1 通过丙基 4-(2-(4,6-二甲氧基嘧啶-2-基)苯甲氨基)苯甲酸酯的水解产生，随后环 A 和环 B 之间的 C-N 键通过氧化和生化降解断裂，生成 M3，然后进一步转化为 M4，最终矿化为 CO(2)；（2）第一步与途径 1 相同，但 M1 首先发生羰基化形成 M2。M2 中环 A 和环 B 之间的 C-N 键通过水解断裂，生成 M3。通过 HPLC 结合放射性分离峰分析还研究了好氧土壤中这四种代谢物的动态变化。在 100 天的孵育后，土壤中发现 1.7-9.7%的施用 [14C]以 M1 的形式存在，0.3-1.1%以 M2 的形式存在，14.5-20.9%以 M3 的形式存在，3.7-6.7%以 M4 的形式存在，而 pH 似乎是影响这些代谢物形成和消散的最具影响力的土壤性质。
