Figure 1.
(A) Plants constitute the best source of nature-derived GPCR ligands. (B) Taste 2, aminergic, as well as opioid and cannabinoid GPCRs are leading targets of natural products. (C) Trend in discovery of small molecules (524) versus peptides (104) as nature-derived GPCR ligands from 1980 to 2018. Ligands before 1980 were not included.