Paderni Daniele, Voccia Maria, Macedi Eleonora, Formica Mauro, Giorgi Luca, Caporaso Lucia, Fusi Vieri
Department of Pure and Applied Sciences, University of Urbino, via Ca' le Suore 2-4, 61029 Urbino, Italy.
Department of Chemistry and Biology, University of Salerno, via Giovanni Paolo II 132, 84084 Fisciano, Salerno, Italy.
Dalton Trans. 2024 Aug 27;53(34):14300-14314. doi: 10.1039/d4dt01791a.
A new palladium(II) complex containing the previously synthesized 4,10-bis[(3-hydroxy-4-pyron-2-yl)methyl]-1,7-dimethyl-1,4,7,10-tetraazacyclododecane ligand maltonis was prepared and characterized both in solution and in the solid state. Hirshfeld surface and energy framework analyses were also performed. Because maltonis already showed antineoplastic activity, the complexation of Pd(II), chosen as an alternative to Pt(II), was investigated to study its possible biological activity. UV-vis and NMR studies confirmed the formation and stability of the complex in aqueous solution at physiological pH. X-ray diffraction data revealed a structure where the Pd(II) ion is lodged in the dimethyl-cyclen cavity, with maltol rings facing each other (closed shape) even if they are not involved in the coordination. DFT analysis was performed in order to understand the most stable shape of the complex. In view of evaluating its possible bioactive conformation, the DFT study suggested a slight energetic preference for the closed one. The resulting closed complex was stabilized in the X-ray structure by intermolecular interactions that replace the intramolecular interactions present in the optimized complex. According to the DFT calculated formation energies, notwithstanding its rarity, the Pd(II) complex of maltonis is the thermodynamically preferred one among analogous complexes containing different metal ions (Pt(II), Co(II), and Cu(II)). Finally, to study its possible biological activity, the interaction between the Pd(II) complex of maltonis and nucleosides was evaluated through NMR and DFT calculations, revealing a possible interaction with purines the maltol moieties.
制备了一种新的钯（II）配合物，其含有先前合成的4,10-双[（3-羟基-4-吡喃-2-基）甲基]-1,7-二甲基-1,4,7,10-四氮杂环十二烷配体麦芽酮，并且在溶液和固态中均进行了表征。还进行了 Hirshfeld 表面和能量框架分析。由于麦芽酮已显示出抗肿瘤活性，因此研究了作为铂（II）替代品的钯（II）的络合作用，以研究其可能的生物活性。紫外可见光谱和核磁共振研究证实了该配合物在生理pH值的水溶液中的形成和稳定性。X射线衍射数据揭示了一种结构，其中钯（II）离子位于二甲基环烯腔内，麦芽酚环相互面对（闭合形状），即使它们不参与配位。进行了密度泛函理论（DFT）分析，以了解该配合物最稳定的形状。鉴于评估其可能的生物活性构象，DFT研究表明对闭合构象有轻微的能量偏好。通过分子间相互作用使所得的闭合配合物在X射线结构中稳定，这些分子间相互作用取代了优化配合物中存在的分子内相互作用。根据DFT计算的形成能，尽管其稀有性，但麦芽酮的钯（II）配合物在含有不同金属离子（铂（II）、钴（II）和铜（II））的类似配合物中是热力学上优选的。最后，为了研究其可能的生物活性，通过核磁共振和DFT计算评估了麦芽酮的钯（II）配合物与核苷之间的相互作用，揭示了与嘌呤 麦芽酚部分可能的相互作用。
