Degradation and residue dynamics of veterinary medicines in soil-plant systems

该项目的目的是描述兽药（磺胺嘧啶，SDZ和二氟沙星，DIF）在存在玉米的粪肥改良土壤中的归宿，即，降解的动力学和质量平衡、矿化速率、母体化合物和代谢物形成的不可浸提残留物（NER）、NER的潜在再活化以及可溶性和结合残留物的结构解析。为此目的以及其他合作伙伴，我们将合成用14 C-和13 C-同位素标记的各种衍生物：（1）[U-苯基-13 C]-SDZ;（2）[U-苯基-13 C]-乙酰基-SDZ;（3）[U-苯基-13 C]-4-羟基-SDZ;（4）[2-嘧啶基-14 C]-N-乙酰基-SDZ;（5）14 C-标记的OH-SDZ。项目组第一部分（[2-嘧啶-14C]-SDZ和[2- 13 C，1- 15 N]-DIF）提供了更多衍生物，这些衍生物将由外部合成实验室（14 C标记的DIF）提供。在与Jülich中心实验尽可能接近的实验条件下，将母体化合物和独立的代谢物Ac-SDZ和OH-SDZ（根据其中一个提议假设）在施用加标粪肥的种植土壤中孵育。对于结合13 C标记残留物的结构研究，将应用样品溶解后的高分辨率NMR和固体样品的CP-MAS NMR光谱。

Aim of the project is to characterize the fate of veterinary pharmaceuticals (sulfadiazine, SDZ, and difloxacin, DIF) in manure amended soil in presence of maize, i.e., the kinetics and mass balance of degradation, mineralization rates, the formation of non extractable residues (NER) by parent compounds and metabolites, the potential remobilization of NER as well as the structural elucidation of soluble and bound residues. For this purpose as well as for other partners we will synthesize various derivatives labelled with 14C- and 13C-isotopes: (1) [U-phenyl-13C]-SDZ; (2) [U-phenyl-13C]-acetyl-SDZ; (3) [U-phenyl-13C]-4-hydroxy-SDZ; (4) [2-Pyrimidyl-14C]-N-acetyl-SDZ; (5) 14C-labelled OH-SDZ. Further derivatives are available from the first part of the project cluster ([2-Pyrimidyl-14C]-SDZ and [2-13C,1-15N]-DIF) and will be provided by external synthetic laboratories (14C-labelled DIF). The parent compounds and independently the metabolites Ac-SDZ and OH-SDZ (according to one of the proposals hypothesis) will be incubated in planted soil applying spiked manure under experimental conditions as close as possible compared to the central experiment performed in Jülich. For structural investigation of the bound 13C-labelled residues high resolution NMR after sample solubilisation and CP-MAS NMR spectroscopy of solid samples will be applied.