Ruthenium(II) ethylenediamine complexes with dipyridophenazine ligands: synthesis, characterization, DNA interactions, and antiproliferative activities

摘要

Ruthenmm(II) complexes, [Ru(en)_2dppz]~(2+) (1), [Ru(en)_2qdppz]~(2+) (2), [Ru(en)_2acdppz]~(2+) (3), and [Ru(en)_2actatp]~(2+) (4), have been synthesized and characterized by IR, ~1H, ~(13)C-NMR and LC-MS. The interactions of these complexes with calf thymus (CT) DNA have been investigated by absorption, emission, viscosity, thermal denaturation, and circular dichroism. These techniques reveal that the complexes bind strongly to DNA. The apparent binding constants for the complexes decrease from 1 to 4 and are in the order of 8.5 ±0.2 × 10~5 M~(-1) (1), 7.3 ±0.8 × 10~5 M~(-1) (2), 4.3±0.3 × 10~5 M~(-1) (3), and 7.5 ±0.5 × 10~4 M~(-1) (4). The plot of log K versus log [Na~+] yield slopes of -1.47, — 1.44, —1.36, and —1.24 for 1, 2, 3, and 4, respectively. These complexes promote the photoclea-vage of pBR322 DNA. Cytotoxicities of these complexes suggest their possible anticancer activity.