Monoamine oxidase (MAO) helps to maintain the homeostasis of biogenic amines through oxidative deamination of amines and thereby regulates emotions, mood, perception, judgement and other cognitive functions. There are two MAO isoenzymes: MAO-A and MAO-B, which are bound to the outer mitochondrial membrane and belong to the group of flavoenzymes. Currently, enzyme inhibitors are being used in the treatment of depression and Parkinson's disease.
Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are enzymes, that hydrolyze the nerve transporter acetylcholine (ACh) to acetic acid and choline. Because of decreased concentrations of acetylcholine in Alzheimer's and several other diseases, AChE inhibitors are used for several therapeutic purposes. BChE inhibitors are still in development but could also be used to treat Alzheimer's disease in the future.
The increased production of pathogenic bacterial species with high resistance to antibiotic therapy poses a serious public health threat. Mur enzymes play an important role in the initial stages of bacterial peptidoglycan biosynthesis and represent an excellent target for future antibacterial agents.
The purpose of our work was to synthesize new potential inhibitors of MAO enzymes, inhibitors of Mur ligases and inhibitors of AChE and BChE. The laboratory work mainly involved the synthesis of 5-styrylnicotinonitrile derivatives, for which we measured the inhibitory activity against these enzymes. The structure of derivatives was designed based on known inhibitors which have already been synthesized at the Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ljubljana. The syntheses were performed mainly with Heck reaction, with the biggest problem of extremely poor yields. We tried to convert synthesized compounds with sufficient yield to 3-styryl-5-(1H-tetrazol-5-yl) pyridine derivatives, which have already proven to be inhibitors of Mur ligases.
Out of all synthesized compounds, 5-(4-methoxy-3-nitrostyryl)nicotinonitrile, with an IC50 value of 0.425 µM on the MAO-B enzyme, proved to be the best inhibitor, which provides potential for the development of new active substances in the field of Parkinson's and other neurodegenerative diseases.
|