Figure 1.

Chemical structures of mOR-EG ligands used in the study, including eugenol, some eugenol derivatives, and the structurally dissimilar compounds mousse cristal, nootkatone, and orivone. Some of the ligands failed to give a measurable response (green). Some ligands activated both PLC- and AC-mediated outputs, seven of them equally (black) and four preferentially favoring the PLC-dependent output (blue). Methyl isoeugenol and isosafrole are known antagonists (red).