Peptidomimetics based on ammonium decasubstituted pillar[5]arenes: Influence of the alpha-amino acid residue nature on cholinesterase inhibition.

Cholinesterase inhibitors are a group of medicines that are widely used for the treatment of cognitive impairments accompanying Alzheimer's disease as well as for the treatment of pathological muscle weaknesses syndromes such as myasthenia gravis. The search for novel non-toxic and effective cholinesterase inhibitors for creating neuroprotective and neurotransmitter agents is an urgent interdisciplinary problem. For the first time, the application of water-soluble pillar[5]arenes containing amino acid residues as effective cholinesterase inhibitors was shown. The influence of the nature of aliphatic and aromatic alpha-amino acid residues (glycine, l-alanine, l-phenylalanine and l-tryptophan) on self-assembly, aggregate's stability, cytotoxicity on A549 and LEK cells and cholinesterase inhibition was studied. It was found that the studied compounds with aliphatic amino acid residues showed a low inhibitory ability against cholinesterases. It was established that the pillar[5]arene containing fragments of l-phenylalanine is the most promising inhibitor of butyrylcholinesterase (IC50 = 0.32 ± 0.01 µM), the pillar[5]arene with l-tryptophan residues is the most promising inhibitor of acetylcholinesterase (IC50 = 0.32 ± 0.01 µM). This study has shown a possible application of peptidomimetics based on pillar[5]arenes to inhibit cholinesterase, as well as control the binding affinity to a particular enzyme in a structure-dependent manner.