Dissymmetric thiosemicarbazone ligands containing substituted aldehyde arm and their ruthenium(II) carbonyl complexes with PPh3/AsPh3 as ancillary ligands: Synthesis, structural characterization, DNA/BSA interaction and in vitro anticancer activity

• New ruthenium(II) carbonyl complexes were synthesized and structurally characterized.
• The complexes exhibited intercalative mode of interaction with CT-DNA and bind with BSA via static interaction.
• The MTT and SRB assays demonstrated that the complexes possess cytotoxic activity against various cancer cell lines.
• The mode of cell death was observed by AO/EB staining method.

A serious of new dissymmetric ruthenium(II) carbonyl complexes of the type [Ru(CO)(EPh3)(L1–2)] (1–4), [E = P or As; L1 = N4-(2-Hydroxy-5-chlorobenzylidene)-2-amino-5-chlorobenzophenone thiosemicarbazone; L2 = N4-(2-Hydroxynaphthalene-1-carbaldehyde)-2-amino-5-chlorobenzophenone thiosemicarbazone] have been synthesized and characterized by several spectroscopic studies. The molecular structure of the ligand L1 and the ruthenium(II) carbonyl complexes (2, 4) have been analyzed by single crystal X-ray studies, and found that the ruthenium(II) complexes possess a distorted octahedral geometry. The DNA binding studies such as emissive titration, Ethidium bromide/Methylene blue (EB/MB) displacement assay and viscometry measurements revealed that the ruthenium(II) complexes bound with calf thymus DNA through intercalative mode with relatively high binding constant values. Further, the interactions of the complexes with bovine serum albumin (BSA) were also investigated using fluorescence spectroscopic methods, which showed that the new complexes could bind strongly with BSA. The complexes (1–4) were tested for DNA and BSA cleavage activities, and the results showed that the complexes exhibited good cleavage properties. In addition, the newly synthesized ruthenium(II) complexes possess better in vitro cytotoxic activities against various cell lines (MCF-7, Hop62, MDA-MB-435) and AO/EB staining method showed that these complexes induced apoptosis of MCF-7 cell lines.

New dissymmetric Schiff base ligands and their ruthenium(II) carbonyl complexes were synthesized and characterized by FT-IR, NMR, UV–Vis and single crystal X-ray diffraction. The synthesized ruthenium(II) complexes were used for biological applications such as DNA/BSA interaction and in vitro anticancer activities.Figure optionsDownload as PowerPoint slide