Benzyloxynitrostyrene analogues - A novel class of selective and highly potent inhibitors of monoamine oxidase B

Abstract

This study examines a series of novel 3-benzyloxy-β-nitrostyrene analogues as a novel class of inhibitors of the monoamine oxidase (MAO) enzymes. MAO inhibitors are considered useful for the treatment of depression and Parkinson's disease, and have recently attracted attention as potential therapeutic agents for a range of disorders including Alzheimer's disease, prostate cancer and certain cardiomyopathies. This study shows that the 3-benzyloxy-β-nitrostyrene analogues are potent inhibitors of the MAO-B isoform with IC₅₀ values in the nanomolar range (39-565 nM). Significantly, effectiveness towards MAO-B inhibition seems to be governed by the introduction of a 4″-fluoro-substituent on the benzyloxy ring, with compound 2b exhibiting the highest degree of MAO-B inhibition potency (IC₅₀ = 0.039 μM) and selectivity (SI = 166) among the compounds investigated. Since some of the 3-benzyloxy-β-nitrostyrene analogues possess potencies that are comparable to that of the reversible inhibitor, safinamide (IC₅₀ = 0.080 μM), it may be concluded that this class may be promising leads for the development of reversible and selective MAO-B inhibitors, that may be useful for the management of Parkinson's disease.

Keywords: 3-benzyloxy-β-nitrostyrene analogues; Benzyloxynitrostyrene; Inhibition; MAO-B; Monoamine oxidase; Parkinson's disease; Slow reversible.