A novel water soluble ligand bridged cobalt(ii) coordination polymer of 2-oxo-1,2-dihydroquinoline-3-carbaldehyde (isonicotinic) hydrazone: evaluation of the DNA binding, protein interaction, radical scavenging and anticancer activity

Abstract

A novel water soluble ligand-bridged cobalt(II) coordination polymer has been synthesized by reacting the new ligand, 2-oxo-1,2-dihydroquinoline-3-carbaldehyde (isonicotinic) hydrazone (H 2 L) with Co (NO 3 ) 2 •6H 2 O and characterized by spectral, analytical and structural methods. Single crystal X-ray diffraction studies revealed that the Co(II) complex, {[Co(H 2 L)(H 2 O) 2 ](NO 3 ) 2 •3H 2 O} n has a slightly distorted octahedral geometry around the central Co(II) ion; the ligand is coordinated through the ONO donor atoms to one Co(II) metal center and bridged through the pyridine nitrogen atom to another similar Co(II) center so as to form a one-dimensional polymeric unit. The interaction of the ligand and the complex with calf thymus DNA (CT-DNA) has been explored by absorption and emission titration methods, which revealed that the compounds could interact with CT-DNA through intercalation. The interactions of the compounds with bovine serum albumin (BSA) were also investigated using UVvisible, fluorescence and synchronous fluorescence spectroscopic methods. The results indicated that the complex exhibited a strong binding to BSA over the ligand. Investigation of the antioxidative properties showed that the polymeric Co(II) complex has a strong radical scavenging potency against hydroxyl radicals, 2,2-diphenyl-1-picrylhydrazyl radicals, nitric oxide and superoxide anion radicals. Further, the cytotoxic effect of the compounds examined on cancerous cell lines, such as human cervical cancer cells (HeLa), human laryngeal epithelial carcinoma cells (HEp-2), human liver carcinoma cells (Hep G2), human skin cancer cells (A431) and non-cancerous NIH 3T3 mouse embryonic fibroblasts cell lines showed that the complex exhibited substantial anticancer activity.

Synthesis, Electronic and Optical Properties of Cobalt(II) Dithiocarbamate Fluorescent Nanowires for Optoelectronic Devices

“…The char residue of Na doped Co(dtc-SB) is ~22%, while in case of I 2 doping this reduces to 17% (Fig. 5) moiety (Raja, Bhuvanesh, & Natarajan, 2012). The third and final mass loss between 490 o C to 780 o C occurs due to decomposition of the organic part of the ligand (Giovagnini et al, 2008).…”

Ni(ii) and Co(ii) complexes of an asymmetrical aroylhydrazone: synthesis, molecular structures, DNA binding, protein interaction, radical scavenging and cytotoxic activity

“…The order of the suppression ratio for DPPHc and OHc is complex 1 > complex 2, while for the NO radicals, the scavenging ability is very close to each other. Even though the DPPHc scavenging ability of complexes were lower than the standards, such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) studied in references, 16 the ability was excellent for the DPPH and OH radicals when compared to the standards radicals (Table 4). The IC 50 values (Table 4) indicated that the various radical scavenging activities of the complexes are in the order of OHc > DPPHc > NOc.…”

“…Many Ni(II) and Co(II) complexes bearing hydrazone ligands are known to have radical scavenging properties. 15,16,71 The radical scavenging activities of our compounds in a cell free system have been examined with reference to hydroxyl radical (OHc), DPPH radical (DPPHc) and nitric oxide (NOc) radical and their corresponding IC 50 values have been tabulated in Table 4. The inhibitory effect of the hydrazone ligand and complexes on radicals was also depicted in Fig.…”

“…To investigate the quenching process further, uorescence quenching data were analyzed with the Stern-Volmer equation and Scatchard equation. 16 The quenching constant (K q ) can be calculated using the plots I 0 /I versus [Q] (shown in Fig. 7) and was found to be 3.67(AE0.…”

“…The bond distances for Co-O1 and Co-O2 are 2.019(3) and 2.007(4)Å, respectively, which are comparable to the bond lengths reported for octahedral Co(II) complexes of aroylhydrazone. 16 The bite angle of phen (N5-Co1-N6 angle) is 74.69 (18) , whereas for the hydrazone ligand, the bite angles vary between 75.63(16) and 76.70 (13) . The distortion, from a regular octahedral geometry is evident from the N2-Co1-N4 trans-bond angle value of 162.49 (17) , while the other two trans angles, O1-Co1-N6 and O2-Co1-N5 are 164.32(17) and 168.22 (14) , respectively.…”