New thiosemicarbazone Schiff base ligands: Synthesis, characterization, catecholase study and hemolytic activity

Dimethoxyindoles based thiosemicarbazones as multi-target agents; synthesis, crystal interactions, biological activity and molecular modeling

Alzheimer's disease (AD) is known as one of the most devastating neurodegenerative disease diagnosed for the old-aged people and cholinesterase inhibitors (ChEI) can be used as an effective palliative treatment for AD. A range of novel monomeric and dimeric indole based thiosemicarbazone derivatives 17-28 was synthesized in order to target cholinesterases (ChE). Biological importance of the targeted compounds 17-28 was investigated by employing the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes along with three different antioxidant property determination assays, namely DPPH free radical scavenging, ABTS cationic radical decolarization, and CUPRAC cupric reducing antioxidant capacity. The compounds 18 and 19 displayed the best inhibitor activity against BChE with IC₅₀ values of 7.42 and 1.95 μM, respectively. The antioxidant potentials were found to be moderate for DPPH and ABTS assays and the compounds 28 and 18 were the most potent candidates for both antioxidant assays. Cupric reducing capacity was the most promising assay and the compounds 25, 26 and 28 provided better inhibition values than all the standards. Further binding mode and affinity studies performed by molecular docking and molecular dynamics simulations. Accordingly, the compound 19 is the most plausible candidate that can compete with galantamine (GNT), a common pharmaceutics targeting both cholinesterase enzymes.

Thiosemicarbazone Complexes of Transition Metals as Catalysts for Cross-Coupling Reactions

Catalysis of cross-coupling reactions under phosphane-free conditions represents an important ongoing challenge. Although transition metal complexes based on the thiosemicarbazone unit have been known for a very long time, their use in homogeneous catalysis has been studied only relatively recently. In particular, reports of cross-coupling catalytic reactions with such complexes have appeared only in the last 15 years. This review provides a survey of the research in this area and a discussion of the prospects for future developments.

Synthesis, molecular modelling, FT-IR, Raman and NMR characterization, molecular docking and ADMET study of new nickel(II) complex with an N4-tetradentate thiosemicarbazone

A new nickel(II) complex was synthesized by using S-propyl-thiosemicarbazide and 2-amino-3,5-dibromobenzaldehyde. The complex, obtained by the template effect of nickel ions, was structurally analysed by experimental and theoretical vibrational spectroscopy, NMR and density functional theory (DFT) calculations. By using DFT/B3LYP method with 6-311++G(d, p) basis set, the most stable molecular structure of the title molecule was calculated. The fundamental vibrational wavenumbers, IR and Raman intensities for the optimized structure of the molecule under investigation were determined and compared with the experimental vibrational spectra. The vibrational assignment was achieved using the calculated potential energy distributions of the vibrational modes. Moreover, the molecular electrostatic potential (MEP), the highest occupied molecular orbital (HOMO) and the lowest occupied molecular orbital (LUMO) energies were calculated, Molecular docking of the molecule was carried out against DNA in order to identify the potential inhibitory action of the title compound. The findings suggested that the aforementioned compound has a strong binding affinity to interact with DNA residues DT8, DC9, DG12, DG16, DA17, and DA18 through the intermolecular hydrogen bonds. Also the performed in silico ADMET analysis was the prediction of the synthesized molecule's pharmacokinetic and toxicity profile expressing good oral drug like actions and non-toxic nature. The complex has been shown to have the possibility to become a model molecule for drug development processes.Communicated by Ramaswamy H. Sarma.

Cu(ii) complexes with tridentate sulfur and selenium ligands: catecholase and hydrolysis activity

Two new copper(ii) mononuclear complexes (CSe and CS) were synthesized and characterized by the following techniques: X-ray crystallography, elemental analysis, IR, EPR and UV-vis spectroscopies, conductimetric analysis and mass spectrometry.