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

Indole-Based Compounds in the Development of Anti-Neurodegenerative Agents

Neurodegeneration is a gradual decay process leading to the depletion of neurons in both the central and peripheral nervous systems, ultimately resulting in cognitive dysfunctions and the deterioration of brain functions, alongside a decline in motor skills and behavioral capabilities. Neurodegenerative disorders (NDs) impose a substantial socio-economic strain on society, aggravated by the advancing age of the world population and the absence of effective remedies, predicting a negative future. In this context, the urgency of discovering viable therapies is critical and, despite significant efforts by medicinal chemists in developing potential drug candidates and exploring various small molecules as therapeutics, regrettably, a truly effective treatment is yet to be found. Nitrogen heterocyclic compounds, and particularly those containing the indole nucleus, which has emerged as privileged scaffold, have attracted particular attention for a variety of pharmacological applications. This review analyzes the rational design strategy adopted by different research groups for the development of anti-neurodegenerative indole-based compounds which have the potential to modulate various molecular targets involved in NDs, with reference to the most recent advances between 2018 and 2023.

Synthesis, characterization, and in vitro anti-cholinesterase screening of novel indole amines

The present study involved the targeted synthesis and characterization of novel indole amines with anti-acetylcholinesterase profiling. A series of proposed indole amines was virtually screened against human acetylcholinesterase. A few indole amines (23, 24, and 25) showing strong enzyme binding in the in silico studies were synthesized in the laboratory and characterized using spectroscopic (IR, UV, NMR, single crystal XRD) and spectrometric (EIMS, HR-EIMS) methods. The indole amine 23 was crystallized from EtOH and analyzed with single crystal XRD. These ligands interacted with the PAS site in the enzyme, and their binding may disrupt the activity. The in vitro acetylcholinesterase inhibition studies revealed that the IC50 values for indole amines 25 and 24 (4.28 and 4.66 μM, respectively) were comparable to that of galantamine (4.15 μM) and may be studied further as cost-effective acetylcholinesterase inhibitors.

Bis-indole substituted phthalocyanines: Photophysical and photochemical properties

Tetra substituted peripheral and non-peripheral Zn(II) phthalocyanines were successfully synthesized employing 4-(bis(3-methyl-1H-indol-2-yl)methyl)phenol as a starting material. The structure of these synthesized compounds was confirmed using 1H NMR, [Formula: see text]C NMR, infrared (IR), UV-vis, and MALDI-TOF spectral data. The photophysical (fluorescence quantum yields and lifetimes) and photochemical (singlet oxygen generation) properties of all synthesized peripheral and non-peripheral compounds were investigated in order to determine the potential of these compounds for application in photodynamic therapy.