Oxidative DNA cleavage, cytotoxicity and antimicrobial studies of l-ornithine copper (II) complexes

Abstract

a b s t r a c tNew ternary copper (II) complexes, [Cu(L-orn)(B)(Cl)](ClÁ2H 2 O) (1-2) where L-orn is L-ornithine, B is an N,N-donor heterocyclic base, viz. 2,2 0 -bipyridine (bpy, 1) and 1,10-phenanthroline (phen, 2), were synthesized and characterized by various spectroscopic techniques. Complex 2 is characterized by the X-ray single crystallographic method. The complex shows a distorted square-pyramidal (4 + 1) CuN 3 OCl coordination sphere. Binding interactions of the complexes with calf thymus DNA (CT-DNA) were investigated by UV-Vis absorption titration, ethidium bromide displacement assay, viscometric titration experiment and DNA melting studies. Complex 2 shows appreciable chemical nuclease activity in the presence of 3-mercaptopropionic acid (MPA). The complexes were subjected to in vitro cytotoxicity studies against carcinomic human alveolar basal epithelial cells (A-549) and human epithelial (HEp-2) cells. The IC 50 values of 1 and 2 are less than that of cisplatin against HEp-2 cell lines. MIC values for 1 against the bacterial strains Streptococcus mutans and Pseudomonas aeruginosa are 0.5 mM.

Design and synthesis of thalidomide based dithiocarbamate Cu(II), Ni(II) and Ru(III) complexes as anticancer agents

“…Present scenario witnesses a huge interest in the design of copper complexes as anticancer agents [9][10][11]. Copper complexes with low molecular weights exhibit copper-zinc-superoxide dismutase mimicking activity and the antitumor activity of certain organocopper compounds has been assumed to be due to their superoxide scavenging ability [12,13].…”

Mononuclear Binary Complex Formation Equilibria of L-Ornithine with Biologically Essential Metals in TBAB Micellar Media

“…The concentration distribution diagrams of M(II)-Orn binary complexes for Co(II), Cu(II) and Ni(II) in Micellar-water mixtures are given in Fig. 1 (11) and (12)]. The decrease in concentration of the free metal to lower values and to zero values at extreme higher pH indicates its strong participation in the complex formation equilibria.…”

“…L-Ornithine (L-Orn) is a non-protein 2,5-diaminopentanoic acid whose metal complexes are insoluble in water and soluble in most organic solvents [9]. It is a tridentate ligand [10,11] and known to form several stable metal ion complexes in a variety of solvents differing in the degree of solubility: with Co(II), Ni(II) and Cu(II) [12][13][14][15][16][17][18][19][20][21][22]; Cd(II), Sn(IV), Ce(IV) and Pd(II) in different solvents [23][24][25][26][27]. L-Ornithine complexes of bio-essential metals play an important role in chemotherapeutic applications [28,29].…”

Solvent-driven structural topology involving energetically significant intra- and intermolecular chelate ring contacts and anticancer activities of Cu(ii) phenanthroline complexes involving benzoates: experimental and theoretical studies

“…A similar results were also reported with copper(II) complex with phenanthroline which induced apoptosis, cell cycle arrest (G0/ G1) and consequently prevent cell proliferations in tumor cell (Sarcoma-180) tested in vitro. 72 Copper complexes with phenanthroline also have DNA binding and cleaving ability 77,78 which may be a possible reason for inducing apoptotic cell death in DL cells by complex 1 and 2. The connection between DNA damage and apoptosis has been very well established and executed by lesion-sensors (MMR), signal transducers (ATM) and transcription regulation.…”