Polish Academy of Sciences, Centre of Polymer and Carbon Materials, 34, M. Curie-Skłodowska Street, 41-819, Zabrze, Poland.
Rapid Commun Mass Spectrom. 2012 Dec 15;26(23):2673-82. doi: 10.1002/rcm.6391.
Due to the low resistance of forms of pesticides to environmental conditions, agrochemicals frequently do not reach their objective, which may cause environmental pollution. The minimisation of the adverse effects of pesticides requires the development of a system for their long-term controlled release. In the present work, we report the synthesis and structural studies of novel controlled-release pesticide-oligo-3-hydroxybutyrate systems with potential agricultural applications.
The novel controlled-release pesticide-oligo(3-hydroxybutyrate) systems were obtained via the anionic ring-opening oligomerisation of (R,S)-β-butyrolactone initiated by the potassium salt of selected pesticides. Electrospray ionisation mass spectrometry (ESI-MS(n)) analyses in positive-ion mode, supported by (1)H NMR results, were used for the structural characterisation of the obtained conjugates. The presence of the respective pesticides in an unchanged form associated with oligo-3-hydroxybutyrate chains was confirmed by ESI-MS/MS experiments performed for selected pesticide-oligo(3-hydroxybutyrate) ions and by the subsequent investigation of their fragmentation pathways.
The structures of the resulting conjugates were established at the molecular level with the aid of ESI-MS(n). The presence of one and two chlorine atoms (derived from MCPA and 2,4-D pesticides) in the conjugates studied was confirmed by comparison of the calculated and experimental isotopic profiles for the selected ions of the respective conjugates. The fragmentation of the selected ions of the resulting conjugates confirmed that the respective pesticides are covalently bonded with oligo(3-hydroxybutyrate) through a hydrolysable ester bond.
An analytical method has been developed for the characterisation of new pesticide-oligo(3-hydroxybutyrate) conjugates. A detailed NMR and MS structural characterisation of the designed controlled-release system of the pesticides was performed. These results are important in the analysis of designed biodegradable polymeric conjugates with potential agricultural applications.
由于农药对环境条件的抵抗力低，农用化学品经常达不到其目标，这可能会造成环境污染。减少农药的不利影响需要开发一种长期控制释放的系统。在本工作中，我们报告了具有潜在农业应用的新型控释农药-低聚 3-羟基丁酸酯系统的合成和结构研究。
通过（R，S）-β-丁内酯的阴离子开环聚合，用选定农药的钾盐引发，得到新型控释农药-低聚（3-羟基丁酸酯）系统。采用正离子模式的电喷雾电离质谱（ESI-MS(n)）分析，并结合 1H NMR 结果，对所得轭合物进行结构表征。通过对选定的农药-低聚（3-羟基丁酸酯）离子进行 ESI-MS/MS 实验以及随后对其碎裂途径的研究，证实了相应的农药以未改变的形式与低聚 3-羟基丁酸酯链存在。
借助 ESI-MS(n)，在分子水平上确定了所得轭合物的结构。通过比较相应轭合物的选定离子的计算和实验同位素分布，证实了研究中轭合物的氯原子（来自 MCPA 和 2,4-D 农药）的存在。所得轭合物的选定离子的碎裂证实了相应的农药通过可水解的酯键与低聚（3-羟基丁酸酯）共价结合。
已经开发出一种用于表征新型农药-低聚（3-羟基丁酸酯）轭合物的分析方法。对设计的农药控释系统进行了详细的 NMR 和 MS 结构表征。这些结果对于分析具有潜在农业应用的设计可生物降解的聚合物轭合物非常重要。
