Wang Chuanyue, Lyon Delina Y, Hughes Joseph B, Bennett George N
Department of Civil and Environmental Engineering, MS-317, Rice University, Houston, Texas 77005-1892, USA.
Environ Sci Technol. 2003 Aug 15;37(16):3595-600. doi: 10.1021/es030010a.
Phytotransformation studies of 2,4,6-trinitrotoluene (TNT) were conducted using Myriophyllum aquaticum to clarify the role of initial intermediates of TNT transformation in the complex product distributions reported previously. 2-Hydroxylamino-4,6-dinitrotoluene (2HA46DNT) and 4-hydroxylamino-2,6-dinitrotoluene (4HA26DNT) were the initial intermediates of TNT phytotransformation. 2HA46DNT and 4HA26DNT were both abiotically transformed to 4,4',6,6'-tetranitro-2,2'-azoxytoluene (2,2'azoxy) and 2,2',6,6'-tetranitro-4,4'-azoxytoluene (4,4'azoxy) and also phytoreduced to the related amines 2-amino-4,6-dinitrotoluene (2A46DNT) and 4-amino-2,6-dinitrotoluene (4A26DNT). To further elucidate the initial steps of this TNT phytotransformation pathway, the transformations of known intermediates (including 2HA46DNT, 4HA26DNT, 2A46DNT, 4A26DNT, 2,2'azoxy, and 4,4'azoxy) were monitored in plant systems. The transformation rates were measured, and kinetic analysis using pseudo-first-order models was used to evaluate the relative rates of competing reactions. The formation of the azoxy products was determined to be more rapid than the formation of the amine products. Both the azoxy and amine products were subject to uptake and further transformation by the plant.
利用水生植物狐尾藻对2,4,6-三硝基甲苯（TNT）进行了植物转化研究，以阐明TNT转化的初始中间体在先前报道的复杂产物分布中的作用。2-羟基氨基-4,6-二硝基甲苯（2HA46DNT）和4-羟基氨基-2,6-二硝基甲苯（4HA26DNT）是TNT植物转化的初始中间体。2HA46DNT和4HA26DNT均非生物转化为4,4',6,6'-四硝基-2,2'-偶氮甲苯（2,2'-偶氮氧基）和2,2',6,6'-四硝基-4,4'-偶氮甲苯（4,4'-偶氮氧基），并且还被植物还原为相关的胺类2-氨基-4,6-二硝基甲苯（2A46DNT）和4-氨基-2,6-二硝基甲苯（4A26DNT）。为了进一步阐明该TNT植物转化途径的初始步骤，在植物系统中监测了已知中间体（包括2HA46DNT、4HA26DNT、2A46DNT、4A26DNT、2,2'-偶氮氧基和4,4'-偶氮氧基）的转化。测量了转化速率，并使用准一级模型进行动力学分析，以评估竞争反应的相对速率。已确定偶氮氧基产物的形成比胺产物的形成更快。偶氮氧基产物和胺产物均会被植物吸收并进一步转化。
