Ten coordination compounds, [Cu(L¹)Cl] (C1), [Cu(L¹)NO₃] (C2), [Cu(L²)Cl] (C3), [Cu(L²)NO₃] (C4), [Cu(L³)Cl] (C5), [Cu(L³)NO₃] (C6), [Cu(L⁴)NO₃] (C7), [Cu(L⁴)Cl] (C8), [Cu(L⁵)Cl] (C9), and [Cu(L⁵)NO₃] (C10), containing pyridine derivatives of N⁴-methoxyphenyl-thiosemicarbazones were synthesized and characterized. The molecular structure of four compounds was investigated using single crystal X-ray diffraction. Spectral analysis techniques such as FT-IR, ¹H NMR, ¹³C NMR, elemental analysis, and molar conductivity were used for all the synthesized compounds. The tested synthesized compounds were evaluated for their anticancer activity and selectivity against a variety of cancer cell lines, including HL-60, LNCaP, MCF-7, HepG-2, K-562, HeLa, BxPC-3, RD, and MDCK normal cell line. Most compounds demonstrated selective anticancer activity superior to doxorubicin. Notably, all ligands showed high antiproliferative activity against HL-60 cells, with IC₅₀ values between 0.01 and 0.06 µM and a selectivity index as high as 5000. Coordination of copper(II) with ligands HL¹ and HL³ notably enhanced antiproliferative activity, lowering the IC₅₀ to 0.03 µM. Additionally, the antioxidant activity of these compounds was assessed, revealing that all tested ligands and most coordination compounds exhibited greater antioxidant activity compared to Trolox, with some ligands showing activity up to 12.3 times higher. Toxicity studies on Daphnia magna indicated low toxicity for the ligands, generally less than doxorubicin, with LC₅₀ values ranging from 13 to 90 µM, suggesting moderate toxicity. Conversely, the coordination complexes were more toxic, with LC₅₀ values between 0.5 and 13 µM.

Ten coordination compounds: [Cu(L1)Cl] (C1), [Cu(L1)NO3] (C2), [Cu(L2)Cl] (C3), [Cu(L2)NO3] (C4), [Cu(L3)Cl] (C5), [Cu(L3)NO3] (C6), [Cu(L4)NO3] (C7), [Cu(L4)Cl] (C8), [Cu(L5)Cl] (C9), [Cu(L5)NO3] (C10) containing pyridine derivatives of N4-methoxyphenyl-thiosemicarbazones were synthesized and characterized. The molecular structure of four compounds was investigated using single crystal X-ray diffraction. Spectral analysis techniques such as FT-IR, 1H, 13C-NMR, and elemental analysis and molar conductivity were used for all the synthesized compounds. The tested synthesized compounds were evaluated for their anticancer activity and selectivity against a variety of cancer cell lines, including LNCaP, MCF-7, HepG-2, K-562, HeLa, BxPC-3, and RD and normal cell line. Most compounds demonstrated selective anticancer activity superior to doxorubicin. Notably, all ligands showed high antiproliferative activity against HL-60 cells, with IC50 values between 0.01 and 0.06 µM, and a selectivity index as high as 10000. Coordination of copper with proligands HL1 and HL3 notably enhanced antiproliferative activity, lowering the IC50 to 0.03 µM. Additionally, the antioxidant activity of these compounds was assessed, revealing that all tested ligands and most coordination compounds exhibited greater antioxidant activity compared to Trolox, with some ligands showing activity up to 12.3 times higher. Toxicity studies on Daphnia magna indicated low toxicity for the ligands, generally less than doxorubicin, with LC50 values ranging from 13 to 90 µM, suggesting moderate toxicity. Conversely, the coordination complexes were more toxic, with LC50 values between 0.5 and 13 µM.