International Joint Research Center for Persistent Toxic Substances, College of Environment , Zhejiang University of Technology , Hangzhou 310014 , China.
J Agric Food Chem. 2018 May 2;66(17):4328-4335. doi: 10.1021/acs.jafc.8b00543. Epub 2018 Apr 20.
Plants can extensively uptake organic contaminants from soil and subsequently transform them into various products. Those compounds containing hydroxyl may undergo direct conjugation with endogenous biomolecules in plants, and potentially be preserved as conjugates, thus enabling overlooked risk via consumptions of food crops. In this study, we evaluated the uptake and metabolism of 2,4-dibromophenol (DBP) by both carrot cells and whole plant. DBP was completely removed from cell cultures with a half-life of 10.8 h. Four saccharide conjugates, three amino acid conjugates, and one phase I metabolite were identified via ultraperformance liquid chromatography quadrupole time-of-flight mass spectrometry analysis. The dibromophenol glucopyranoside (glucose conjugate) was quantitated by synthesized standard and accounted for 9.3% of the initial spiked DBP at the end of incubation. The activity of glycosyltransferase was positively related to the production of 2,4-dibromophenol glucopyranoside ( p = 0.02, R = 0.86), implying the role of enzymatic catalysis involved in phase II metabolism.
植物可以从土壤中广泛吸收有机污染物，随后将其转化为各种产物。那些含有羟基的化合物可能会与植物内源性生物分子发生直接共轭，并可能作为共轭物被保留下来，从而通过食用农作物而被忽视风险。在这项研究中，我们评估了 2,4-二溴苯酚（DBP）在胡萝卜细胞和整株植物中的吸收和代谢。DBP 在细胞培养物中的半衰期为 10.8 小时，完全被去除。通过超高效液相色谱四极杆飞行时间质谱分析，鉴定了 4 种糖缀合物、3 种氨基酸缀合物和 1 种 I 相代谢物。通过合成标准品定量测定了二溴苯酚吡喃葡萄糖苷（葡萄糖缀合物），在孵育结束时占初始添加 DBP 的 9.3%。糖基转移酶的活性与 2,4-二溴苯酚吡喃葡萄糖苷的生成呈正相关（p=0.02，R=0.86），这表明酶催化在 II 相代谢中发挥作用。
