Structural pharmacology and therapeutic potential of 5-methoxytryptamines.
Warren, A.L., Lankri, D., Cunningham, M.J., Serrano, I.C., Parise, L.F., Kruegel, A.C., Duggan, P., Zilberg, G., Capper, M.J., Havel, V., Russo, S.J., Sames, D., Wacker, D.(2024) Nature 630: 237-246
- PubMed: 38720072 
- DOI: https://doi.org/10.1038/s41586-024-07403-2
- Primary Citation of Related Structures:  
8FY8, 8FYE, 8FYL, 8FYT, 8FYX - PubMed Abstract: 
Psychedelic substances such as lysergic acid diethylamide (LSD) and psilocybin show potential for the treatment of various neuropsychiatric disorders 1-3 . These compounds are thought to mediate their hallucinogenic and therapeutic effects through the serotonin (5-hydroxytryptamine (5-HT)) receptor 5-HT 2A (ref. 4 ). However, 5-HT 1A also plays a part in the behavioural effects of tryptamine hallucinogens 5 , particularly 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), a psychedelic found in the toxin of Colorado River toads 6 . Although 5-HT 1A is a validated therapeutic target 7,8 , little is known about how psychedelics engage 5-HT 1A and which effects are mediated by this receptor. Here we map the molecular underpinnings of 5-MeO-DMT pharmacology through five cryogenic electron microscopy (cryo-EM) structures of 5-HT 1A , systematic medicinal chemistry, receptor mutagenesis and mouse behaviour. Structure-activity relationship analyses of 5-methoxytryptamines at both 5-HT 1A and 5-HT 2A enable the characterization of molecular determinants of 5-HT 1A signalling potency, efficacy and selectivity. Moreover, we contrast the structural interactions and in vitro pharmacology of 5-MeO-DMT and analogues to the pan-serotonergic agonist LSD and clinically used 5-HT 1A agonists. We show that a 5-HT 1A -selective 5-MeO-DMT analogue is devoid of hallucinogenic-like effects while retaining anxiolytic-like and antidepressant-like activity in socially defeated animals. Our studies uncover molecular aspects of 5-HT 1A -targeted psychedelics and therapeutics, which may facilitate the future development of new medications for neuropsychiatric disorders.
Organizational Affiliation: 
Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.