硫杂蒽酮类稀土配合物的合成、表征及与DNA的作用(I)

合成了新的O-(硫杂蒽酮-2]-基)-氧乙酸及其稀土配合物. 通过元素分析, IR, ¹H NMR, UV, DTA-TG和¹³C NMR谱对其结构进行了表征. 研究表明: 配体羧羰基脱质子后与金属离子配位, 2位氧原子也与金属离子配位, 配合物中含有一定量的配位水, 配合物为非电解质类型. 同时, 研究了O-(硫杂蒽酮-2]-基)-氧乙酸稀土配合物对质粒DNA的切割作用. 结果表明: 铕的配合物对DNA的切割较明显, 且当配合物浓度增加时, 质粒DNA的超螺旋构型逐渐减少, 而缺刻、开环型构型逐渐增多. 在相同条件下, Eu(III)离子对质粒pBR322DNA几乎没有切割作用; 配体O-(硫杂蒽酮-2]-基)-氧乙酸对质粒pBR322DNA也有切割作用, 但配合物EuL₃对质粒pBR322DNA的切割作用明显强于配体, 表明稀土离子Eu(III)与配体生成配合物后有较好的协同切割作用.

Synthesis, Characterization of the Complex of Thiaxanthone with Rare Earth and the Interactions between the Complex and DNA (I)

The complexes of thiaxanthon-2-yl-oxyacetate with rare earths were synthesized. The structure of such complexes was characterized by elemental analysis, IR, ¹H NMR, UV, DTA-TG and ¹³C NMR spectrum. The results suggested that their composition should be M∶L＝1∶3 (M＝RE^3＋, L＝thiaxanthon-2-yl-oxyacetate), the metal should be coordinated to not only carboxylic oxygen but also ether oxygen, and the complex should be non-electrolyte with coordinating water molecule. The interaction between the Eu(III) complex of thiaxanthon-2-yl-oxyacetate and plasmid DNA was studied by agarose gel electrophoresis. The data showed that the cleavage of plasmid DNA might depend on the concentration of the complex. The higher concentration of the complex caused the larger decrease of DNA super helix. Under the same concentration, the complex and thiaxanthon-2-yl-oxyacetate had obvious plasmid DNA cleavage ability but Eu(III) had very little. The complex had stronger plasmid DNA cleavage ability than ligand. The results suggested that rare earth ions had good synergism with ligand in cleavage of plasmid DNA.