Jevtovic Violeta, Perendija Stefan, Alrashidi Aljazi Abdullah, Alreshidi Maha Awjan, Alzahrani Elham A, Alshammari Odeh A O, Hussien Mostafa Aly, Dimitrić Marković Jasmina, Dimić Dušan
Department of Chemistry, College of Science, University of Ha'il, Ha'il 81451, Saudi Arabia.
Faculty of Physical Chemistry, University of Belgrade, Studentski Trg 12-16, 11158 Belgrade, Serbia.
Int J Mol Sci. 2025 May 30;26(11):5289. doi: 10.3390/ijms26115289.
The coordination chemistry, structural characterization, and biomolecular interactions of europium(III) and iron(III) complexes with the pyridoxal-semicarbazone (PLSC) ligand were thoroughly examined using experimental and computational approaches. Single-crystal X-ray diffraction revealed that the europium complex exhibits a nine-coordinate geometry with one protonated and one deprotonated PLSC ligand and nitrato and aqua ligands. In contrast, the iron complex adopts a six-coordinate structure featuring a monoprotonated PLSC, two chlorido, and an aqua ligand. Hirshfeld surface analysis confirmed the significance of intermolecular contacts in stabilizing the crystal lattice. Theoretical geometry optimizations using DFT methods demonstrated excellent agreement with experimental bond lengths and angles, thereby validating the reliability of the chosen computational levels for subsequent quantum chemical analyses. Quantum Theory of Atoms in Molecules (QTAIM) analysis was employed to investigate the nature of metal-ligand interactions, with variations based on the identity of the donor atom and the ligand's protonation state. The biological potential of the complexes was evaluated through spectrofluorimetric titration and molecular docking. displayed stronger binding to human serum albumin (HSA), while showed higher affinity for calf thymus DNA (CT-DNA), driven by intercalation. Thermodynamic data confirmed spontaneous and enthalpy-driven interactions. These findings support using PLSC-based metal complexes as promising candidates for future biomedical applications, particularly in drug delivery and DNA targeting.
采用实验和计算方法深入研究了铕（III）和铁（III）与吡哆醛缩氨基脲（PLSC）配体形成的配合物的配位化学、结构表征及生物分子相互作用。单晶X射线衍射表明，铕配合物呈现九配位几何结构，含有一个质子化和一个去质子化的PLSC配体以及硝酸根和水配体。相比之下，铁配合物采用六配位结构，具有一个单质子化的PLSC、两个氯配体和一个水配体。 Hirshfeld表面分析证实了分子间接触对稳定晶格的重要性。使用密度泛函理论（DFT）方法进行的理论几何优化表明，其与实验键长和键角具有良好的一致性，从而验证了所选计算水平用于后续量子化学分析的可靠性。采用分子中的原子量子理论（QTAIM）分析来研究金属-配体相互作用的本质，其会因供体原子的身份和配体的质子化状态而有所不同。通过荧光光谱滴定和分子对接评估了配合物的生物活性。 与人血清白蛋白（HSA）表现出更强的结合力，而 对小牛胸腺DNA（CT-DNA）表现出更高的亲和力，这是由插入作用驱动的。热力学数据证实了自发和焓驱动的相互作用。这些发现支持将基于PLSC的金属配合物作为未来生物医学应用的有前景的候选物，特别是在药物递送和DNA靶向方面。
