Synthesis, characterization, UV-Vis absorption and cholinesterase inhibition properties of bis-indolyl imine ligand systems

Abstract

A number of bis-indolyl imine helical structures has successfully been synthesized employing Schiff base reaction conditions starting from 4,6-dimethoxy-2,3-diphenylindole with different o-phenyl diamines as pi-spacer bridged. The structures of targeted compounds were identified by FT-IR, mass, H-1 and C-13 NMR spectroscopy along with single crystal X-ray diffraction techniques. The ground state absorption properties of the bis-indolyl compounds were also investigated utilizing UV-Vis absorption spectroscopy. As the biological aspect of the synthesized compounds, the anticholinesterase potency was investigated towards the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. The highest inhibition was determined in the presence of compound 9 with the values of 89.21 and 96.06, better than standard Galantamine, for AChE and BChE, respectively. (C) 2020 Elsevier B.V. All rights reserved.