New Ruthenium(II)-arene complexes appended curcumin based hydrazones: synthesis, spectral characterization, anti-oxidant and anticancer studies

Curcumin derived Schiff bases and their half-sandwich Ru(II) arene complexes were synthesized and characterized via various spectral techniques. Spectral analysis confirmed the proposed molecular stoichiometry of the complexes, in which the ligands bound to ruthenium ion in a bidentate manner through their azomethine nitrogen (neutral coordination) and anionic nitrogen (formed after enolisation). The antioxidant property of the compounds was analyzed in terms of radical scavenging ability with DPPH, ABTS, superoxide, hydroxyl and nitric oxide and the complexes possessed significant antioxidant activity. Anticancer activity was investigated against A549 (human lung cancer) and HeLa (human cervical cancer) cell lines, in which the compounds exhibited an activity better than the standard drugs employed. Overall, the activities of the ruthenium(II) complexes were found to be more than their parent ligands due to chelation and the obtained results highlighted the strong possibility to develop highly active ruthenium arene complexes as anticancer agents. Graphical abstract