Analytical and behavioral characterization of 1-dodecanoyl-LSD (1DD-LSD).

A novel LSD derivative, 1-dodecanoyl-LSD (1DD-LSD), was synthesized and tested in mice to see if it produces LSD-like effects. The compound induced a head-twitch response in C57BL/6J mice with a median effective dose of 2.17 mg/kg (3.60 μmol/kg). LSD was 27-fold more potent than 1DD-LSD under similar conditions. Other homologues, such as ALD-52 and 1-propanoyl-LSD, also showed considerably higher potency, suggesting that hydrolysis of the 1-dodecanoyl moiety may be less efficient in vivo. The increased lipophilicity of 1DD-LSD might cause it to be sequestered in fat, reducing enzymatic hydrolysis. Further studies are needed to assess its activity in humans and its potential as a long-acting prodrug for LSD.

Study at a glance

Abstract

1-Acetyl-N,N-diethyllysergamide (1A-LSD, ALD-52) was first synthesized in the 1950s and found to produce psychedelic effects similar to those of LSD. Evidence suggests that ALD-52 serves as a prodrug in vivo and hydrolysis to LSD is likely responsible for its activity. Extension of the N1-alkylcarbonyl chain gives rise to novel lysergamides, which spurred further investigations into their structure-activity relationships. At the same time, ALD-52 and numerous homologues have emerged as recreational drugs ("research chemicals") that are available from online vendors. In the present study, 1-dodecanoyl-LSD (1DD-LSD), a novel N1-acylated LSD derivative, was subjected to analytical characterization and was also tested in the mouse head-twitch response (HTR) assay to assess whether it produces LSD-like effects in vivo. When tested in C57BL/6J mice, 1DD-LSD induced the HTR with a median effective dose (ED50) of 2.17 mg/kg, which was equivalent to 3.60 μmol/kg. Under similar experimental conditions, LSD has 27-fold higher potency than 1DD-LSD in the HTR assay. Previous work has shown that other homologues such as ALD-52 and 1-propanoyl-LSD also have considerably higher potency than 1DD-LSD in mice, which suggests that hydrolysis of the 1-dodecanoyl moiety may be comparatively less efficient in vivo. Further investigations are warranted to determine whether the increased lipophilicity of 1DD-LSD causes it to be sequestered in fat, thereby reducing its exposure to enzymatic hydrolysis in plasma and tissues. Further clinical studies are also required to assess its activity in humans and to test the prediction that it could potentially serve as a long-acting prodrug for LSD.