5-Nitrotryptamine, also known as Nitro-I, is a serotonin receptor modulator and psychedelic drug of the tryptamine family.[1][2] It is the 5-nitro derivative of tryptamine.[1][2]

The drug is a biased agonist of the serotonin 5-HT2A receptor (Ki = 490–2,050 nM; EC50Tooltip half-maximal effective concentration = 0.11–491 nM; EmaxTooltip maximal efficacy = 44–108%).[1][2] It shows high selectivity (10-fold) for activation of the Gαq pathway over β-arrestin2 recruitment and very high selectivity (>50-fold) for activation of the Gαq pathway over the Gαi1 pathway.[1]

Given via intracerebroventricular injection, Nitro-I produces the head-twitch response, a behavioral proxy of psychedelic effects, in rodents.[1] This effect is absent in serotonin 5-HT2A receptor knockout mice.[1] Unlike 5-phenoxytryptamine (OVT2), Nitro-I does not produce serotonin 5-HT2A receptor-mediated long-term memory deficits.[1]

The chemical synthesis of Nitro-I has been described.[3]

Nitro-I was first described in the scientific literature by 1953.[3] Subsequently, it was studied and described in greater detail in 2015[2] and 2024.[1]

See also

References

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  2. 1 2 Shaw E, Woolley DW (1953). "The Synthesis of Nitro- and Aminoindoles Analogous to Serotonin". Journal of the American Chemical Society. 75 (8): 1877–1881. doi:10.1021/ja01104a029. ISSN 0002-7863. Retrieved 1 March 2026.
source: https://en.wikipedia.org/wiki/5-Nitrotryptamine