<p>A novel palladium(II) complex with the violurate ligand, [Pd(H₂L)₂], was synthesized and characterized. Molar conductivity (15.55 Ω<sup>-1</sup> cm² mol<sup>-1</sup>) confirmed its non-electrolytic nature, and ESI-MS showed a molecular ion peak at m/z 417.57 matching [C₈H₄N₆O₈Pd]⁺. PXRD structural analysis revealed a triclinic crystal system (space group P-1) with τ₄ = 0.04, confirming square-planar geometry around Pd(II), with Pd–O bond lengths ranging from 2.065 to 2.178 Å. Thermal analysis showed three decomposition stages (41.00%, 15.00%, and 18.50% mass losses) with palladium metal as the final residue. The complex exhibited DNA binding constants of K<sub>b</sub> = 1.694 × 10⁴ M<sup>-1</sup> (UV-Vis) and 2.870 × 10<sup>7</sup> M<sup>-1</sup> (fluorescence) with ΔG = -24.12 and − 42.94&#xa0;kJ mol<sup>-1</sup>, respectively, indicating groove binding mode as confirmed by viscosity measurements. HSA binding constants were K<sub>b</sub> = 2.784 × 10<sup>5</sup> M<sup>-1</sup> (UV-Vis) and 6.546 × 10<sup>9</sup> M<sup>-1</sup> (fluorescence). Cytotoxicity assays against MDA-MB-231, HCT-116, and HepG-2 cell lines gave IC₅₀ values of 29.42, 38.11, and 24.68 µM, respectively, with selectivity indices (1.99, 1.78, and 1.29) higher than cisplatin. The complex induced late apoptosis (8.46-fold increase) via p53/caspase-3 upregulation (4.46-fold and 3.96-fold, respectively). DFT calculations showed reduced HOMO-LUMO gap (5.406&#xa0;eV vs. 6.517&#xa0;eV for free ligand), correlating with enhanced bioactivity. These findings present [Pd(H₂L)₂] complex as a promising dual-targeting anticancer candidate. Unlike conventional Pd(II) complexes that target DNA via intercalation or N/S coordination, our complex employs an unusual O₄ coordination sphere from violurate ligands, demonstrating a non-intercalative groove-binding mode and a p53/caspase-3 mediated apoptosis with enhanced selectivity index.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Synthesis, structural characterization, and dual DNA/HSA binding of novel Palladium(II) violurate complex with selective p53/Caspase-3-mediated anticancer activity

  • Maged A. El-Kemary,
  • Abd El-Motaleb,
  • M. Ramadan,
  • Heba A. Sahyon,
  • Asmaa A. Shabbat,
  • Ahmed M. Fathy

摘要

A novel palladium(II) complex with the violurate ligand, [Pd(H₂L)₂], was synthesized and characterized. Molar conductivity (15.55 Ω-1 cm² mol-1) confirmed its non-electrolytic nature, and ESI-MS showed a molecular ion peak at m/z 417.57 matching [C₈H₄N₆O₈Pd]⁺. PXRD structural analysis revealed a triclinic crystal system (space group P-1) with τ₄ = 0.04, confirming square-planar geometry around Pd(II), with Pd–O bond lengths ranging from 2.065 to 2.178 Å. Thermal analysis showed three decomposition stages (41.00%, 15.00%, and 18.50% mass losses) with palladium metal as the final residue. The complex exhibited DNA binding constants of Kb = 1.694 × 10⁴ M-1 (UV-Vis) and 2.870 × 107 M-1 (fluorescence) with ΔG = -24.12 and − 42.94 kJ mol-1, respectively, indicating groove binding mode as confirmed by viscosity measurements. HSA binding constants were Kb = 2.784 × 105 M-1 (UV-Vis) and 6.546 × 109 M-1 (fluorescence). Cytotoxicity assays against MDA-MB-231, HCT-116, and HepG-2 cell lines gave IC₅₀ values of 29.42, 38.11, and 24.68 µM, respectively, with selectivity indices (1.99, 1.78, and 1.29) higher than cisplatin. The complex induced late apoptosis (8.46-fold increase) via p53/caspase-3 upregulation (4.46-fold and 3.96-fold, respectively). DFT calculations showed reduced HOMO-LUMO gap (5.406 eV vs. 6.517 eV for free ligand), correlating with enhanced bioactivity. These findings present [Pd(H₂L)₂] complex as a promising dual-targeting anticancer candidate. Unlike conventional Pd(II) complexes that target DNA via intercalation or N/S coordination, our complex employs an unusual O₄ coordination sphere from violurate ligands, demonstrating a non-intercalative groove-binding mode and a p53/caspase-3 mediated apoptosis with enhanced selectivity index.