Ethnobotany and the Role of Plant Natural Products in Antibiotic Drug Discovery

The crisis of antibiotic resistance
necessitates creative and innovative
approaches, from chemical identification and analysis to the assessment
of bioactivity. Plant natural products (NPs) represent a promising
source of antibacterial lead compounds that could help fill the drug
discovery pipeline in response to the growing antibiotic resistance
crisis. The major strength of plant NPs lies in their rich and unique
chemodiversity, their worldwide distribution and ease of access, their
various antibacterial modes of action, and the proven clinical effectiveness
of plant extracts from which they are isolated. While many studies
have tried to summarize NPs with antibacterial activities, a comprehensive
review with rigorous selection criteria has never been performed.
In this work, the literature from 2012 to 2019 was systematically
reviewed to highlight plant-derived compounds with antibacterial activity
by focusing on their growth inhibitory activity. A total of 459 compounds
are included in this Review, of which 50.8% are phenolic derivatives,
26.6% are terpenoids, 5.7% are alkaloids, and 17% are classified as
other metabolites. A selection of 183 compounds is further discussed
regarding their antibacterial activity, biosynthesis, structure–activity
relationship, mechanism of action, and potential as antibiotics. Emerging
trends in the field of antibacterial drug discovery from plants are
also discussed. This Review brings to the forefront key findings on
the antibacterial potential of plant NPs for consideration in future
antibiotic discovery and development efforts.