Synthesis of New Cationic Schiff Base Complexes of Copper(II) and Their Selective Binding with DNA
作者:Tomohide Tanaka、Keiko Tsurutani、Atsushi Komatsu、Toyofumi Ito、Kazumi Iida、Yuki Fujii、Yoshiharu Nakano、Yoshiharu Usui、Yutaka Fukuda、Makoto Chikira
DOI:10.1246/bcsj.70.615
日期:1997.3
A series of cationic salen-type Schiff base complexes of copper(II), the general formula of which is [CuR3N+–CH2–C6H3(O−)–CH=N–}2X]Br2 (R: CH3, C2H5, C3H7, C4H9; X: C2H4, C3H6, C6H10, C6H4, C10H6), was newly prepared, and the molecular structure of complex 1 (R = CH3, X = C2H4) was determined by an X-ray crystal structure analysis. The binding mode and binding constants (Kb) of all the complexes with calf thymus DNA were investigated at an ionic strength of I = 0.05(NaCl + HEPES buffer, pH = 7.2) using induced CD and the UV-vis spectra. Those complexes with aliphatic X group selectively bound to the groove of DNA, and the Kb’s were in the range of 102—103 mol dm−3 (site size base pairs n = 7.2—7.4). However, those with aromatic X group selectivity intercalated to the base pairs, and the Kb’s were in the range of 104—105mol dm−3 (n = 2.8—4.0). These binding modes were confirmed based on the salt dependence of Kb’s. In addition, 1 and 10 (R = CH3, X = C6H4) were found to exhibit AT-sequence affinity from the induced CD spectra and Kb’s for poly(dA-dT)–poly(dA-dT), poly(dG-dC)–poly(dG-dC), and poly(dA-dC)–poly(dT-dG).
一系列阳离子Salen型Schiff碱
铜(II)络合物被新配制,其一般式为[CuR3N+–
CH2–
C6H3(O−)–CH=N–}2X]Br2(R:
CH3,
C2H5,
C3H7,
C4H9;X:
C2H4,
C3H6,
C6H10,
C6H4,
C10H6),并通过X射线晶体结构分析确定了络合物1(R = ,X = )的分子结构。以离子强度I = 0.05(NaCl +
HEPES缓冲液,pH = 7.2)为条件,使用诱导圆二色谱(CD)和紫外可见光谱研究了所有络合物与小牛胸腺DNA的结合模式和结合常数(Kb)。那些具有脂肪族X基团的络合物选择性地结合到DNA的槽口,Kb的范围在102—103 mol dm−3(位点基对数n = 7.2—7.4)。而具有芳香族X基团的络合物则选择性地插入到基对中,Kb的范围在104—105 mol dm−3(n = 2.8—4.0)。这些结合模式基于Kb的盐依赖性得到了确认。此外,发现1和10(R = ,X = )在诱导CD光谱和针对聚(dA-dT)–聚(dA-dT)、聚(dG-dC)–聚(dG-dC)和聚(dA-dC)–聚(dT-dG)的Kb中表现出AT序列亲和力。