Preparation, characterizations and biological evaluations of new copper(II) complexes containing ONO pincer type ligands

Dual sensing of methionine and aspartic acid in aqueous medium by a quinoline-based fluorescent probe

A quinoline-based Schiff base sensor, 6-methyl-2-oxo-1,2-dihydro-quinoline-3-carboxaldehyde-4(N)-phenylsemicarbazone (6MPS), has been developed for selective sensing of methionine and aspartic acid in aqueous medium through "on-off-on" type selective detection of copper ion. Fluorescence imaging of 6MPS, 6MPSC, 6MPSCN, 6MPSC-met, 6MPSCN-met, 6MPSC-asp and 6MPSCN-asp has been successfully demonstrated, in which the sensing probes 6MPSC-met, 6MPSCN-met, 6MPSC-asp and 6MPSCN-asp displayed bright green fluorescence in both in vitro and in vivo live cells.

Novel nickel(II), palladium(II), and platinum(II) complexes having a pyrrolyl-iminophosphine (PNN) pincer: Synthesis, crystal structures, and cytotoxic activity

A pyrrolyl-iminophosphine (PNNH) which would act as a potential terdentate ligand has been prepared by Schiff base reaction. Complexes [M(PNN)X] (M = Ni; X = Cl (1), Pd; X = Cl (2), Br (3), I (4), M = Pt; X = Cl (5)) were prepared. The title complexes were characterized by various spectroscopic (IR, ¹H, ¹³C, and ³¹P NMR) and elemental analyses. The molecular structures of 1, 2, and 5 have been established by single-crystal X-ray crystallography, demonstrating a distorted square planar geometry comprising two 5-membered metallacyclic rings. Complexes 1 and 2 were found to crystallize in the orthorhombic while complex 5 crystallizes in the monoclinic. Cytotoxicities of the complexes along with PNNH were evaluated against A549 (lung), SK-OV-3 (ovarian), SM-MEL-2 (skin), and HCT15 (colon) human cancer cell lines by sulforhodamine B assay. Notably, the palladium(II) complex (2) shows the highest activity. Apoptosis activity along with the caspase inhibitor Z-VAD (Z-Val-Ala-Asp-fluoromethyl ketone) assay of 2 and 5 against A549 and HCT15 cancer cell lines were investigated to learn a mechanistic pathway for the observed cytotoxicity, practically eliminating an apoptotic cell-death route. Complexes 2 and 5 were studied to DNA cleavage assay and molecular docking simulation. The DNA (pcDNA3.0) cleavage experiment evaluates complex 5 interacting with DNA, more effectively, in comparison to complex 2. Molecular docking simulation of 2 and 5 toward DNA and GRP78 (glucose-regulated protein 78) was performed to predict binding sites of ligand-receptors and a plausible mechanistic aspect of metallodrug-action.

Synthesis and spectral characterizations of water soluble Cu(ii) complexes containing N-heterocyclic chelates: cell-proliferation, antioxidant and nucleic acid/serum albumin interactions

Water soluble N-heterocyclic copper(ii) complexes were synthesized, characterized and studied their DNA/protein binding interactions, antioxidation and antiproliferative potentials. The complex 4 found to be better than other complexes.

A quinoline-based probe for effective and selective sensing of aspartic acid in aqueous medium: in vitro and in vivo live cell imaging

A highly sensitive and selective “on–off–on” chemosensor for aspartic acid in aqueous solution was established. In vitro live cell imaging against MCF 7 cells and in vivo imaging using C. elegans were successfully demonstrated.