苯乙烯-DNA加合特性的研究

目的 研究苯乙烯的DNA加合特性。方法 采用紫外光谱移动法测定苯乙烯－7，8－氧化物（SO）、苯乙烯、苯乙醇酸（MA）、苯乙醛酸（PGA）、苯乙烯巯基尿酸（UMA）和DNA的加合反应；以^32P后标记法研究SO－DNA加合物；以气相色谱－质谱、核磁共振研究SO－DAN加合物的结构。结果 苯乙烯、MA、PGA和UMA不与DNA发生加合反应；SO分别在DNA脱氧鸟苷碱基上的O^6位、N^2位形成6种加合物。结论 苯乙烯进入机体后，通过其活性中间代谢物SO与DNA起加合作用，SO攻击DNA脱氧鸟苷碱基上的O^6位、N^2位形成加合物，如果在细胞复制前所形成的DNA加合物没有被修复或者被错误修复的话，就有可能导致基因突变，产生化学损伤。苯乙烯的其他代谢物未见此效应。

A study on the adduct characteristics of styrene and DNA

Objective To explore the adduct characteristics of styrene and DNA. Methods The adduct reactions between styrene,urinary mandalic acid(MA),phenylglyoxalic acid(PGA),mercapturic acid of styrene(UMA) and DNA were studied by ultraviolet spectral analysis.The SO-DNA adducts by 32P-post labeled method,the chemical structures of SO-DNA adducts by GC-MS and NMR were also studied. Results SO combined with DNA at O6,N2 positions of dGMP to form six adducts,but styrene,urinary mandalic acid,phenylglyoxalic acid and mercapturic acid of styrene did not react with DNA to form adduct. Conclusions Styrene formed adduct with DNA through its active center metabolite-SO after entering the body.SO combined with DNA at O6,N2 positions of dGMP to form adducts.If these DNA adducts are not repaired or are mis-repaired before cell duplication,the gene mutation and chemical damage would happen.No adduct reactions are seen among other metabolites of styrene.