Afsar Ali

Cobalt complex as building blocks: synthesis, characterization, and catalytic applications of {Cd2+-Co3+-Cd2+} and {Hg2+-Co3+-Hg2+} heterobimetallic complexes.

The present work demonstrates the utilization of the Co(3+) complex of pyridine-amide ligand as building blocks for the assembly of heterobimetallic complexes. These Co(3+)-centered building blocks orient the tethered pyridine groups to a preorganized cleft that successively coordinates to the Cd(2+) and Hg(2+) ions in the periphery. Both {Cd(2+)-Co(3+)-Cd(2+)} and {Hg(2+)-Co(3+)-Hg(2+)} heterobimetallic complexes have been thoroughly characterized, including crystal structures depicting interesting weak interactions in the solid state. The {Cd(2+)-Co(3+)-Cd(2+)} and {Hg(2+)-Co(3+)-Hg(2+)} heterobimetallic complexes have been further used for the catalytic cyanosilylation of imines and ring-opening reactions of oxiranes and thiiranes. The results suggest peripheral metal-selective catalytic reactions.

Synthesis, characterization and self-assembly of Co3+ complexes appended with phenol and catechol groups

AbstractThis work presents the syntheses, characterization and hydrogen bonding based self-assembly of Co3+ complexes of pyridine-amide based bidentate ligands containing appended phenol and catechol groups. Placement of multiple hydrogen bond donors (phenolic OH and amidic NH groups) and acceptors (Oamide groups) in these molecules results in interesting self-assembled architectures. Graphical AbstractCobalt complexes of pyridine-amide based bidentate ligands containing appended phenol and catechol groups are discussed. Placement of multiple hydrogen bond donors and acceptors in these coordination complexes results in interesting self-assembly.

Syntheses, characterization, and anti-cancer activities of pyridine-amide based compounds containing appended phenol or catechol groups

AbstractSeveral pyridine-amide compounds appended with phenol/catechol groups are synthesized. These compounds consist of protected or deprotected phenol/catechol groups and offer pyridine, amide, and phenol/catechol functional groups. All compounds have been well-characterized by various spectroscopic methods, elemental analysis, thermal studies, and crystallography. The biological activities of all compounds were investigated while a few compounds significantly decreased the metabolic viability, growth and clonogenicity of T98G cells in dose dependent manner. Accumulation of ROS was observed in T98G cells, which displayed a compromised redox status as evident from increased cellular Caspase 3/7 activity and formation of micronuclei. The in silico pharmacokinetic studies suggest that all compounds have good bioavailability, water solubility and other drug-like parameters. A few compounds were identified as the lead molecules for future investigation due to their: (a) high activity against T98G brain, H-460 lung, and SNU-80 thyroid cancer cells; (b) low cytotoxicity in non-malignant HEK and MRC-5 cells; (c) low toxic risks based on in silico evaluation; (d) good theoretical oral bioavailability according to Lipinski ‘rule of five′ pharmacokinetic parameters; and (e) better drug-likeness and drug-score values. Graphical AbstractPyridine-amide compounds appended with protected (1P-6P) and deprotected (1-6) phenol/catechol groups were synthesized and characterized. These compounds are efficacious on various cancer cells and less toxic to normal human cells.