LPD-824

N-Pyrrolidyllysergamide (LPD-824), also known as lysergic acid pyrrolidide (LA-Pyr), is a psychedelic drug of the lysergamide family related to lysergic acid diethylamide (LSD).^[1][2][3][4] It is the analogue of LSD in which the N,N-diethylamide moiety has been cyclized into an N,N-pyrrolidide ring.^[1][2]

LPD-824

Clinical data
Other names	LPD-824; LPD824; N-Pyrrolidyllysergamide; Lysergic acid pyrrolidide; LA-Pyr; LSD-Pyr
Drug class	Serotonin receptor modulator; Serotonin 5-HT2A receptor agonist; Serotonergic psychedelic; Hallucinogen
Identifiers
IUPAC name (8β)-6-Methyl-8-(pyrrolidin-1-ylcarbonyl)-9,10-didehydroergoline
CAS Number	2385-87-7 Y
PubChem CID	200628
ChemSpider	173678 Y
ChEMBL	ChEMBL302524 Y
CompTox Dashboard (EPA)	DTXSID20946653
Chemical and physical data
Formula	C20H23N3O
Molar mass	321.424 g·mol−1
3D model (JSmol)	Interactive image
SMILES O=C(N1CCCC1)[C@@H]4C=C3c5cccc2c5c(c[nH]2)C[C@H]3N(C4)C
InChI InChI=1S/C20H23N3O/c1-22-12-14(20(24)23-7-2-3-8-23)9-16-15-5-4-6-17-19(15)13(11-21-17)10-18(16)22/h4-6,9,11,14,18,21H,2-3,7-8,10,12H2,1H3/t14-,18-/m1/s1 Y Key:SETDYMMXQQXCRP-RDTXWAMCSA-N Y
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Use and effects

The drug has been reported to have mild and relatively short-lasting LSD-like effects in humans at an oral dose of 800 μg equivalent to one-tenth this amount of LSD (i.e., 80 μg).^[1][5][6] Based on different clinical studies, it is estimated to be 5 to 10% as potent as LSD in humans.^[5][7] Its duration was shorter than that of LSD, lasting around 5 hours as opposed to 7 hours in the case of LSD.^[6] The drug produced nausea at small doses in humans, which was dose-limiting in terms of evaluating its effects.^[8]

Pharmacology

LPD-824 is known to be a serotonin receptor modulator, including of the serotonin 5-HT_2A receptor, where it acted as a partial agonist with about 17-fold lower potency than LSD but an efficacy slightly higher than that of LSD in terms of phosphatidylinositol (PI) hydrolysis.^[2][9][3][4] It also showed affinities for the serotonin 5-HT_2C and 5-HT_1A receptors similar to those of LSD.^[2][9][3]

It had about 5 to 10% of the potency of LSD in preclinical studies with animals, for instance in terms of serotonin antagonism in the rat uterus and hyperthermia in rabbits.^[5][7][10] It is described as a very strong hypotensive agent in animals.^[8] In subsequent rodent drug discrimination tests, LPD-824 fully substituted for LSD, albeit with only about 16 to 25% of the potency.^[11][12]

History

LPD-824 was first described in the scientific literature by Albert Hofmann and colleagues by 1955.^{[13][14][15][16]}

See also

• Substituted lysergamide
• Lysergic acid pyrrolinide (LPN)
• Lysergic acid morpholide (LSM-775)
• Lysergic acid piperidide (LSD-Pip)
• Lysergic acid 2,4-dimethylazetidide (LA-SS-Az, LSZ)