Structural characterization, DNA binding properties and molecular docking studies of imine compounds derived from Disperse black 9

A Series of Biguanide Ligands and Their Cu(II) Complexes: Cholinesterase Inhibitory and Antimicrobial Properties

In this work, a series of biguanide hydrochloride salts and their Cu(II) complexes were synthesized and screened for their acetyl/butyryl choline esterase inhibitory and antimicrobial properties. The structures of the synthesized compounds were characterised by common spectroscopic and analytical methods. Biguanide compounds showed considerably lower inhibitory activity compared to the reference drugs donepezil and galantamine. On the other hand, complexation of the biguanide compounds with Cu(II) resulted in dramatic increase in the inhibitory activity. The Cu(II) complexes showed AChE inhibitory activity with the IC50 values of 21.29±0.95-82.53±0.20 μM and those values are comparable to that of donepezil (IC50 : 18.54±1.03 μM). The synthesised compounds were also screened for their antimicrobial activity towards gram positive (+) and gram negative (-) bacteria. Compounds (12.50 mg/mL) showed important antibacterial properties with inhibition zones of 8-28 mm diameter against gram-positive and gram-negative microorganisms. Compounds A03 and A08 exhibited more antimicrobial properties towards E. coli than standard antibiotics amikacin and gentamicin.

Synthesis, DNA Binding Properties, Molecular Docking and ADME Studies of Schiff Base Compound Containing Pyridine-Propargyl Group

The structure of the pyridine-based Schiff base compound containing the propargyl group was characterized by NMR spectroscopy. Binding of compound 2 with double-stranded fish sperm DNA (Fsds-DNA) was investigated using viscosity measurement studies and UV/VIS and fluorescence spectral techniques. Binding of compound 2 with Fsds-DNA results in minor hypochromism with no change in absorption maxima and fluorescence quenching with almost no shift in emission maxima, which can be attributed to the groove-binding mode of the interaction. The binding constant was found to be 4.7×104  M-1 . The Fsds-DNA viscosity measurement, KI quenching and NaCl quenching studies and the competitive interaction between compound 2 and ethidium bromide with DNA confirm the proposed binding mode. In addition, interactions between compound 2 and the DNA double helix were analysed by molecular docking study in order to determine the binding mode and binding affinity. As a result of molecular docking, the binding affinity of the 2-DNA complex, which has the most stable conformation -8.10 kcal/mol and it is located in its minor groove. In addition, molecular docking and ADME studies for compound 2 were also performed.

The biguanide-sulfonamide derivatives: synthesis, characterization and investigation of anticholinesterase inhibitory, antioxidant and DNA/BSA binding properties

A number of new biguanidine-sulfonamide derivatives (1-16) were synthesized and their structures were characterized by spectroscopic and analytical methods. Crystal structures of the compounds 1, 4, 8, 10 and 14 were determined by single crystal X-ray diffraction studies. X-ray crystallographic data showed the π-electron delocalization through the biguanide units. The AChE and BChE cholinesterase inhibitor, DPPH antioxidant and DNA/BSA binding properties of the synthesized compounds were evaluated. Results of cholinesterase inhibitory properties have shown that the compounds containing electron-withdrawing (-F, -Cl) groups have higher AChE/BChE inhibitory and antioxidant activities. Compound 3 showed higher BChE inhibitory activity than tacrine with IC50 value of 28.4 µM. The compounds interact with DNA via minor groove binding mode. The compounds with a naphthyl group in its structure strongly binds with DNA/BSA biomolecules.Communicated by Ramaswamy H. Sarma.