Interaction of a ruthenium(II)–chalcone complex with double stranded DNA: Spectroscopic, molecular docking and nuclease properties

The interaction of a well characterized new complex 1cis,fac-[RuCl(dmso-S)3(L)] LH = 1-(2-hydroxyphenyl)-3-(4-chlorophenyl) propenone with Calf-thymus DNA (CT-DNA) is monitored using UV–vis titration (Kb = 3.8 × 107) and ethidium bromide displacement studies (Ksv = 3.2). The molecular docking of the complex with DNA sequence d(ACCGACGTCGGT)2 reveals that complex is stabilized by additional electrostatic and hydrogen bonding interaction with DNA besides probable displacement of a labile DMSO by the N7 of guanine. The coordination of guanine is further supported by the isolation and characterization of its adduct with the complex 1.gua (gua = guanine). The nuclease property of complex 1 in the absence and presence of different activators and trappers demonstrates that complex efficiently cleaves supercoiled pBR322 plasmid DNA and binds through major groove of the DNA.

A newly synthesized complex cis,fac-[RuCl(dmso-S)3(L)] (LH = 1-(2-hydroxyphenyl)-3-(4-chlorophenyl) propenone) binds with DNA and cleaves a supercoiled pBR322 plasmid DNA via oxidative pathway.Figure optionsDownload as PowerPoint slideHighlights
► A Ru(II) complex [Ru(L)(dmso)3Cl] containing chalcone is synthesized and characterized using spectral and X-ray crystallographic data.
► In vitro DNA binding studies of the complex is carried out using absorption and emission spectral studies.
► The docked structure of complex with DNA sequence d(ACCGACGTCGGT)2 showed its interaction mainly through phenyl ring inside the DNA major groove.
► DNA is cleaved by the complex from 20 to 100 μM.
► At lower concentration 40 μM, the cleavage of DNA is activated by well known activators and cleavage follows the oxidative pathway.