溴鼠灵与DNA作用机制的光谱研究

农用化学物质残留可能会与DNA结合形成加和物，从而对动物和人类造成危害。文章利用紫外光谱和荧光光谱研究了溴鼠灵(BDF)与小牛胸腺DNA(ct-DNA)的作用机理。结果表明，低浓度的ct-DNA可使BDF的吸收光谱发生减色，ct-DNA对BDF的稳态荧光有明显的的猝灭作用，属于静态猝灭方式，27 ℃时K_SV=1.21×104 L·mol-1;根据热力学参数推测BDF与ct-DNA之间的相互作用主要是范德瓦耳斯力作用;猝灭试验发现ct-DNA对BDF无明显保护作用;离子强度改变时，BDF/ct-DNA体系的荧光强度也随之改变;ct-DNA对β-CD/BDF包络物的荧光也有猝灭，但猝灭程度比游离的BDF有所降低，表明β-CD对BDF具有保护作用，也说明BDF与ct-DNA或β-CD的结合具有竞争性。各试验结果一致表明BDF与ct-DNA之间主要是以沟区结合方式发生作用。另外，试验结果也表明BDF与ct-DNA之间还存在静电作用。范德瓦耳斯力和静电作用的共同作用，为BDF在沟区与DNA的相互结合提供了更好条件。

Study of the Interaction Mechanism between Brodifacoum and DNA by Spectroscopy

The interaction between brodifacoum (3-3-(4'-bromophenyl-4)1,2,3,4-tetralin-10]-4-hydroxyl-coumarin) (BDF),an anticoagulant rodenticide,and calf thymus DNA (ct-DNA) was studied by UV spectrum and fluorescence spectrum. The results were summarized as follows:There was a hypochromic effect of low concentration ct-DNA on the UV spectra. The fluorescence quenching studies showed a regular decrease in the fluorescence intensity after addition of ct-DNA by the static quenching mode with a quenching constant (KSV...