Yang Xuewei, Qi Peipei, Wang Xiangyun, Wang Zhiwei, Sun Yuhan, Wang Lidong, Xu Xiahong, Xu Hao, Wang Qiang, Wang Xinquan, Zhao Changshan
Northeast Agricultural University , Harbin 150030, P. R. China.
Institute of Quality and Standard of Agro-products, Zhejiang Academy of Agricultural Sciences , Hangzhou 310021, P. R. China.
J Agric Food Chem. 2017 Sep 27;65(38):8295-8301. doi: 10.1021/acs.jafc.7b02877. Epub 2017 Sep 19.
Pyrisoxazole is a chiral fungicide with high sterilizing activity to the plant pathogenic bacteria and thus can be used for protecting the vegetables from gray mold, powdery mildew, and brown rot. The present work aimed to explore its stereoselective degradation in cabbage, pakchoi, and pepper samples. The enantioseparation and analysis on chiral column Lux Cellulose-3 based on liquid chromatography tandem mass spectrometry was developed coupled to the QuEChERS method. The recoveries of the stereoisomers in various vegetables ranged from 72.6 to 124% with RSD lower than 5.0%. Enantioselective dissipation of pyrisoxazole in vegetables displayed that (-)-A-pyrisoxazole was preferentially degraded versus (+)-A-pyrisoxazole in all the vegetables. (+)-B-pyrisoxazole was preferentially degraded in cabbage, while there was no obvious enantioselectivity in pakchoi and pepper. Meanwhile, stereoselectivity analysis demonstrated that (±)-A-pyrisoxazole was degraded faster than (±)-B-pyrisoxazole in pakchoi and pepper, while there was no stereoselective degradation in cabbages.
吡唑恶唑是一种对植物病原菌具有高杀菌活性的手性杀菌剂，因此可用于保护蔬菜免受灰霉病、白粉病和褐腐病的侵害。本研究旨在探讨其在卷心菜、小白菜和辣椒样品中的立体选择性降解。基于液相色谱串联质谱联用的QuEChERS方法，建立了在Lux Cellulose-3手性柱上的对映体分离和分析方法。各种蔬菜中立体异构体的回收率在72.6%至124%之间，相对标准偏差低于5.0%。吡唑恶唑在蔬菜中的对映体选择性降解表明，在所有蔬菜中，(-)-A-吡唑恶唑比(+)-A-吡唑恶唑优先降解。(+)-B-吡唑恶唑在卷心菜中优先降解，而在小白菜和辣椒中没有明显的对映体选择性。同时，立体选择性分析表明，在小白菜和辣椒中，(±)-A-吡唑恶唑比(±)-B-吡唑恶唑降解得更快，而在卷心菜中没有立体选择性降解。
