MAO inhibitors and their wider applications: a patent review

INTRODUCTION: Monoamine oxidase (MAO) inhibitors, after the initial 'golden age', are currently used as third-line antidepressants (selective MAO-A inhibitors) or clinically enrolled as co-adjuvants for neurodegenerative diseases (selective MAO-B inhibitors). However, the research within this field is always increasing due to their pivotal role in modulating synaptic functions and monoamines metabolism. AREAS COVERED: In this paper, MAO inhibitors (2015-2017) are disclosed ordering all the patents according to their chemical scaffold. Structure-activity relationships (SARs) are extrapolated for the most investigated chemotypes (coumarins, pyrazole/oxazepinones, (hetero)arylamides). 108 Compounds are divided into two main groups: newly synthesized molecules and naturally-occurring metabolites. Finally, new therapeutic options are outlined to ensure a more complete view on the potential of these inhibitors. EXPERT OPINION: New proposed MAO inhibitors are endowed with a marked isoform selectivity, with innovative therapeutic potential toward other targets (gliomas, inflammation, muscle dystrophies, migraine, chronic pain, pseudobulbar affect), and with a promising ability to address multi-faceted pathologies such as Alzheimer's disease. The increasing number of patents is analyzed collecting data from 2002 to 2017.