苦味酸稀土配合物的合成及其与BSA/DNA的键合作用研究

Synthesis of Picric Acid Rare Earth Complex and Its Bonding Effect on BSA/DNA

合成以N为中心的具有三脚架形结构的配体L及其稀土配合物。用元素分析、核磁共振波谱、紫外吸收光谱、红外光谱、热分析、计算化学等方法对它们的结构进行表征,通过光谱学、电化学等方法研究稀土配合物与BSA,ct-DNA的键合方式和结合位点。结果表明:1个L中2个羰基上的O、磷酰基上的1个O及磷酸根上的1个O与稀土离子配位,L与苦味酸盐以1∶1的形式结合。配合物对BSA的内源荧光以静态猝灭方式猝灭,293 K下二者之间的K_(sv)=5.97×10~5L·mol^(-1),K_q=10^(13)L·mol^(-1)·s,K=1.0×10~5L·mol^(-1),n=1,存在的作用力主要是氢键和范德华力。加入Fe^(3+),Cu^(2+)后,二者之间的作用点不变、结合常数增大,说明Fe^(3+),Cu^(2+)参与了反应且起到增强的作用。Eu(Ⅲ)配合物与ct-DNA以较强的插入作用结合,在测定电位区间内为电化学活性物质。可为该类稀土配合物与蛋白质之间的作用,有效药物在生物体内的药效发挥,新型DNA杂交指示剂的研究提供参考。

Ligand L and its rare earth complex with tripod structured ligand which concentrated on N were syn- thesited. Their structure was characterized with elemental analysis, nuclear magnetic resonance spectrum, ultravio- let absorption spectrum, infrared spectroscopy, thermal analysis and caleulational chemistry. The bonding mode and bonding site of rare earth complex and BSA, ct-DNA with optical spectroscopy, electrochemistry, ere were studied. The result showed that two carbonyl O atoms, one phosphoryl O and one phosphate radical O within one L coordinated with rare earth ion, and L combined with picrate at the form of ratio 1 ： 1. The complex quenches BSA intrinsic fluorescence in static mode, Ksv = 5.97 × 105 L·mol-1, Kq = 1013 L·mol-1·s, K = 1.0 ×105L·mol-1 , n = 1 between the two complexes under 293 K, and the acting forces are mainly hydrogen bond and Van der Waals＇ force. The application point between the two remains unchanged of Fe3＋ , Cu2＋ , which shows that, Fe3 ＋ , Cu2＋ are involved in , and association constant magnifies after addition the reaction and play an enhanced role. Eu （ Ⅲ） combines with ct-DNA by strong intercalation, appearing as electrochemical active substance within the potentio- metric range. The reaction between this rare earth complex and protein and the effect of effective drug in living or- ganisms can provide reference for study of new DNA hybridization indicator.