New Peripheral Pyridine‐Substituted Cobalt, Copper, and Manganese Phthalocyanines as Potential In Vitro Acetyl/Butyrylcholinesterase Inhibitors in the Treatment of Alzheimer's Disease

ABSTRACT In this research, we designed phthalocyanine compounds that are thought to be used as potential acetyl/butyrylcholinesterase inhibitors in the treatment of Alzheimer's disease. First, phthalonitrile compound ( PNM‐CN ), which is the precursor compound for phthalocyanines, was synthesized. Then, by cyclotetramerizing this compound, pyridine‐substituted peripheral cobalt ( PNM‐CoPc ), copper ( PNM‐CuPc ), and manganese ( PNM‐MnClPc ) phthalocyanine compounds were synthesized, and their structures were described using mass, NMR (except phthalocyanines), FT‐IR, and UV–Vis (except phthalonitrile) spectroscopic techniques. Investigations were carried out into the new pyridine‐substituted peripheral ( PNM‐Cu/Co/MnClPcs ) phthalocyanines' in vitro inhibitory properties against butyrylcholinesterase (BuChE) and acetylcholinesterase (AChE). With an IC 50 of 5.95 ± 2.12 μM (AChE) and 0.74 ± 0.01 μM (BuChE), PNM‐CuPc showed the most potent inhibitory effect against AChE and BuChE among all compounds.