Two chiral alkanolamine Schiff base Cu(ii) complexes as potential anticancer agents: synthesis, structure, DNA/protein interactions, and cytotoxic activity

Abstract

Two Schiff base copper(II) complexes, [Cu(R-L) (CH₃OH)]₈ (1) and [Cu(S-L) (CH₃OH)]₄ (2) {[R/S-H₂L = R/S-3-phenyl-2-(2-hydroxy-5-chlorobenzylideneamino)propane-1-ol]}, have been successfully achieved and fully characterized by single-crystal X-ray diffraction (SXRD), mass spectrometry (MS), Fourier transform infrared spectroscopy (FT-IR), and elemental analysis (EA). The interactions of complexes 1 and 2 with calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) have been comprehensively investigated using various electronic absorption spectroscopies. The thermal denaturation, viscosity, and UV-Vis spectra data suggested non-intercalative binding between DNA and the complexes. Additionally, an in vitro cytotoxicity test on the two complexes towards four types of human cancerous cell lines (HL-60, Caco-2, A549, and HeLa) indicated that the two complexes exhibited substantial cytotoxic activity. Especially, complex 2 exhibited excellent data, with IC₅₀ = 10.97 ± 1.22 against HL-60 cells, which indicated that the two chiral complexes play significant roles in the cytotoxicity and interactions with DNA and BSA.