Abstract

Two water-soluble nickel (II) Schiff base complexes were prepared and their interaction with fish sperm DNA (FS-DNA) was investigated by various methods including UV–vis spectroscopy, fluorescence spectroscopy, cyclic voltammetry, and viscometric measurements. Complex 1: [N,N′-bis{5-[(triphenyl phosphonium chloride)-methyl] salicylidine}-3,4-diaminobenzophenone]nickel(II) perchloride dihydrate: [Ni(5-CH₂PPh₃-3,4-salophen)] (ClO₄)₂.2 H₂O was synthesized as a new complex and characterized by elemental analysis, IR, ¹H NMR, thermal gravimetric analysis (TGA) and UV–vis spectroscopy. Complex 2: sodium [(N,N′-bis(5-sulfosalicyliden)-3, 4-diaminobenzophenone)aqua] nickel(II) hydrate: Na₂[Ni (5-SO₃-3,4-salbenz)(H₂O)]. H₂O was already synthesized by our research team, but in this study, its function as a DNA-binding compound was tested, and compared with the results of complex 1-DNA binding. The calculation of different constants using absorption and emission data, all confirmed the stronger binding ability of complex 1 than complex 2 with DNA. Different thermodynamic parameters showed the interactions between DNA and complexes were the type of hydrophobic interaction for complex 1 and electrostatic interaction for complex 2. Also, the negative values of free energy changes proved a spontaneous DNA binding process. Based on cell toxicity assay against two different cell lines including Jurkat and MCF-7, the effect of complex 1 was comparable to cisplatin, and the toxicity mechanism was further justified by bright field microscopy, flow cytometry, and cleavage of DNA in the presence of H₂O₂. Besides, the docking calculations suggested intercalation after measuring the lowest-energy between the complexes and DNA. For both complexes, all analytical, spectroscopic, and molecular modeling methods supported partial intercalation as the main binding mode between the complexes and DNA.

摘要

制备了两种水溶性镍 (II) 席夫碱络合物，并通过各种方法研究了它们与鱼精子 DNA (FS-DNA) 的相互作用，包括紫外-可见光谱、荧光光谱、循环伏安法和粘度测量。配合物1：[N,N'-双{5-[(三苯基氯化磷)-甲基]水杨基}-3,4-二氨基二苯甲酮]高氯化镍(II)二水合物：[Ni(5-CH 2 _PPh 3 _-3 , 4-salophen)] (ClO ₄ ) ₂ .2 H ₂ O被合成为一种新的配合物，并通过元素分析、IR、¹ H NMR、热重分析(TGA)和紫外-可见光谱对其进行了表征。络合物 2：钠 [(N,N'-双(5-磺基水杨酸)-3, 4-二氨基二苯甲酮)水]镍(II)水合物：Na₂ [Ni(5-SO ₃ -3,4-salbenz)(H ₂ O)]。氢₂O 已经由我们的研究团队合成，但在本研究中，测试了它作为 DNA 结合化合物的功能，并与复杂的 1-DNA 结合的结果进行了比较。利用吸收和发射数据计算不同的常数，都证实了复合物1比复合物2与DNA的结合能力更强。不同的热力学参数表明DNA与复合物之间的相互作用是复合物1的疏水相互作用和复合物2的静电相互作用。此外，自由能变化的负值证明了自发的DNA结合过程。基于对包括 Jurkat 和 MCF-7 在内的两种不同细胞系的细胞毒性试验，复合物 1 的作用与顺铂相当，并且在存在 H ₂ O ₂的情况下通过明视野显微镜、流式细胞术和 DNA 裂解进一步证实了毒性机制。此外，对接计算建议在测量复合物和 DNA 之间的最低能量后插入。对于这两种复合物，所有分析、光谱和分子建模方法都支持部分嵌入作为复合物与 DNA 之间的主要结合模式。