Detection and genotoxicity of nitroarenes in ambient air and surface soil

大阪和爱知县表层土壤有机提取物在不添加S9的情况下对鼠伤寒沙门氏菌TA98表现出较强的诱变作用，其诱变量为1240 ~ 233000株/mg。采用Sephadex LH-20柱和硅胶柱进行层析分离。随后，使用Ultra pack ODS柱将具有强诱变性的组分分离为5个组分，Fr. 1 - Fr. 5。这5个组分对各土壤浸出物总诱变力的贡献率相似；Fr. 1: 45%；Fr 2: 15%；Fr 3: 25%；弗4:5；弗5:10 %。用高效液相色谱法对这5个组分进行了进一步分离。结果发现，Fr. 1和Fr. 3的致突变能力分别归因于二硝基芘（DNP）和3,6-二硝基苯并[e]芘（DNBeP）。从各土壤提取物中分离出主要诱变剂Fr. 2、Fr. 4和Fr. 5，根据质谱推测这些诱变剂为硝基芳烃。这些诱变剂在高效液相色谱中的保留时间与环境中检测到的亚硝基甲苯的保留时间不一致。3,6- dnbep在没有S9混合的TA98中表现出极强的诱变性，诱导285,000个回变物/nmol。这种效力与1,8- dnp相当，后者是迄今为止报道的最强诱变剂。由于3,6- dnbep在YG1024中表现出比TA98更高的致突变性，3,6- dnbep被认为是由o -乙酰转移酶激活的致突变性。

Organic extracts from surface soil samples collected in Osaka and Aichi prefectures showed potent mutagenicity in S.typhimurium TA98 in the absence of S9 mix, inducing 1,240 - 233,000 revertants/mg of organic extract. Each soil extract was separated by chromatography using a Sephadex LH-20 column and a silica gel column. The fractions with potent mutagenicity were subsequently separated into five fractions, Fr. 1 - Fr. 5, using an Ultra pack ODS column. The contribution ratios of these five fractions to the total mutagenicity of each soil extract were similar ; Fr. 1 : 45% ; Fr. 2 : 15% ; Fr. 3 : 25% ; Fr. 4 : 5 ; Fr. 5 : 10%. These five fractions were further separated by HPLC. In consequence, it was found that mutagenic potencies of Fr. 1 and Fr. 3 were attributed to dinitropyrene (DNP) and 3,6-dinitrobenzo[e]pyrene (DNBeP), respectively. Major mutagens in Fr. 2, Fr. 4, and Fr. 5 were isolated from each soil extract, and these mutagens were expected to be nitroarenes on the basis of their mass spectra. Retention times of these mutagens in HPLC were not consistent with those of nitrosrenes, which had been detected in the environment. 3,6-DNBeP showed extremely potent mutagenicity in TA98 without S9 mix, inducing 285,000 revertants/nmol. This potency was comparable to that of 1,8-DNP, which is the strongest mutagen reported to date. Because 3,6-DNBeP showed higher mutagenicity in YG1024 than TA98, 3,6-DNBeP was thought to be activated by O-acetyltranferase for mutagenicity.