Table 3. Inhibition Constants of Tryptamine Psychedelic NPS in Competition Binding Assays for Non-5-HT Receptor Targets^a.

	Ki (nM)
Drug	H1	KOR	NR2B	Sigma 1	Sigma 2	Alpha2A	Alpha2B	Alpha2C	SERT
4-PrO-DMT	1,481	4,745	6,250	-	1,349	-	-	-	-
4-HO-MET	483	-	>10,000	-	-	1,666	-	-	1,830
4-AcO-MET	1,720	-	-	7,077	-	-	1,681	-	-
4-HO-DET	1,079	-	8,720	-	3,026	-	-	-	1,800
4-AcO-DET	-	-	2,936	-	-	1,965	1,095	-	-
4-HO-MPT	92	-	3,658	891	1,166	3,625	1,844	-	910
4-AcO-MPT	493	-	-	1,512	-	1,300	453	1,447	-
4-HO-EPT	406	-	5,947	1,400	1,773	2,073	-	-	1,257
4-AcO-EPT	1,024	-	8,111	-	3,497	1,135	274	1,329	-
4-HO-DiPT	-	-	-	1,063	2,215	-	-	-	816
4-HO-MALT	815	-	NT	1,413	2,525	535	-	-	355
4-AcO-MALT	2,603	-	NT	3,471	-	387	1,169	-	-
4-HO-DALT	355	-	-	1,846	1,770	2,670	2,084	2,280	657
4-AcO-DALT	874	-	-	-	4,190	482	214	803	-

^aRadioligands, reference control compound, and control K_i values for each radiolabeled binding site were as follow: H₁ = [³H]pyrilamine vs chlorpheniramine maleate (K_i = 2–6 nM), KOR = [³H]U69593 (2007-07-27) vs Salvinorin A (K_i = 2–6 nM), NR2B = [³H]ifenprodil vs ifenprodil (K_i = 2–7 nM), sigma 1 = [³H]pentazocine vs haloperidol (K_i = 12–32 nM), sigma 2 = [³H]DTG vs haloperidol (K_i = 36–61 nM), alpha_2A = [³H]rauwolscin vs oxymetazoline HCl (K_i = 5–14 nM), alpha_2B = [³H]rauwolscin vs yohimbine (K_i = 6–10 nM), alpha_2C = [³H]rauwolscin vs oxymetazoline HCl (K_i = 23–74 nM), SERT = [³H]citalopram vs amitriptyline (K_i = 12–43 nM). Control K_i values represent the range of inhibition constants across 2–3 experiments run in triplicate. NT = not tested. Dash indicates <50% inhibition in the primary radioligand binding screen.