A Photoswitchable Inhibitor of the Human Serotonin Transporter.

The human serotonin transporter (hSERT) terminates serotonergic signaling through reuptake of neurotransmitter into presynaptic neurons and is a target for many antidepressant drugs. We describe here the development of a photoswitchable hSERT inhibitor, termed azo-escitalopram, that can be reversibly switched between trans and cis configurations using light of different wavelengths. The dark-adapted trans isomer was found to be significantly less active than the cis isomer, formed upon irradiation.