Recent progress in the development of β2 adrenergic receptor agonists: a patent review (2015-2020)

Introduction The β2 adrenergic receptor (β2AR) is a member of G protein-coupled receptors (GPCRs) that mediate the majority of cellular responses to external stimuli. The agonists to this receptor can cause smooth muscle relaxation, therefore many β2AR agonists have been developed especially for the treatment of pulmonary disorders such as asthma and chronic obstructive pulmonary disease (COPD). They remain the first-line therapeutic drugs for such diseases today. Many new natural and synthetic compounds have been discovered and developed as novel β2AR agonists over the past five years. Areas covered This review offers an update for the development of β2AR agonists in the patents published from 2015 to 2020, including new natural and synthetic compounds for the treatment of asthma and COPD. In particular, the latest patents about compounds possessing both muscarinic receptor antagonist and β2 adrenergic receptor agonist activity are reviewed. Such dual-acting compounds are expected to be particularly useful for treating pulmonary disorders because these compounds can be formulated and administered as a single therapeutic agent but, once administered, they are able to provide bronchodilation through two distinct, and possibly synergistic, modes of action. Expert opinion β2AR agonists have been developed extensively for the treatment of asthma and COPD. In the past five years, novel agonists from both natural sources and synthetic methods were intensively developed. Compounds possessing both muscarinic receptor antagonist and β2AR agonist activity represent a new trend in this area because they are possibly able to act together in a synergistic fashion therefore relieve the symptoms of patients as much as possible through two distinct mechanisms.