Epimerization Studies of LSD Using 1H Nuclear Magnetic Resonance (NMR) Spectroscopy
S. J. Salamone, Z. Li, A. J. Mcnally, S. Vitone, Rongyi Wu
Journal of Analytical Toxicology October 1, 1997 DOI: 10.1093/jat/21.6.492 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Experimental study Peer reviewed |
|---|---|
| Duration | One week at 45°C or two weeks at 37°C for LSD to iso-LSD; six weeks at 45°C and pH 9.7 for iso-LSD to LSD |
| Topics | LSD |
| Keywords | Epimer Proton nmr Analytical chemistry journal Chromatography Stereochemistry Biochemistry |
| Citations | 23 |
| Key findings | The equilibrium concentration for LSD to iso-LSD epimerization is a 9:1 ratio (K = 9), achieved at temperatures above 37 °C and pH above 7.0, with iso-LSD requiring more vigorous conditions to reach equilibrium. |
Abstract
A study was conducted to determine the conditions needed to achieve the equilibrium concentration for the epimerization of d-lysergic acid diethylamide (LSD) to iso-LSD. The reaction was followed by integration of the C-9 resonance of LSD and iso-LSD by proton nuclear magnetic resonance (NMR). The C-9 resonance of LSD and iso-LSD appear as singlets at 6.35 and 6.27 ppm respectively. Starting with pure LSD, the conversion to iso-LSD is attained at temperatures above 37 degrees C and pH levels over 7.0. At a pH of 7.0 or higher, the LSD/iso-LSD ratio of 9:1 is achieved after one week at 45 degrees C or two weeks at 37 degrees C. Starting with iso-LSD, the conversion to LSD requires more vigorous conditions. The 9:1 LSD/iso-LSD ratio is attained only after 6 weeks at a temperature of 45 degrees C and a pH of 9.7. At lower pH levels, the reaction proceeds more slowly. The 9:1 LSD/iso-LSD ratio is achieved whether the starting material is LSD or iso-LSD and therefore represents an equilibrium concentration (K = 9). In addition, the more vigorous conditions needed to achieve equilibrium of iso-LSD to LSD demonstrate the difficulty in extraction of the epimerizable proton of iso-LSD. This study is the first to quantitate the epimerization of LSD by NMR techniques and establishes the conditions needed to induce epimerization in solution.
Comparable studies
Other experimental studies on LSD, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Neural correlates of the LSD experience revealed by multimodal neuroimaging. Human participants | 2016 | Experimental study | |
| Crystal structure of an LSD-bound human serotonin receptor | 2017 | Experimental study with structural biology and molecular dynamics simulations | |
| Lysergic Acid Diethylamide: Sensitive Neuronal Units in the Midbrain Raphe Midbrain neurons containing serotonin | 1968 | Experimental study | |
| Connectome-harmonic decomposition of human brain activity reveals dynamical repertoire re-organization under LSD. Human brain | 2017 | Experimental study | |
| LSD-Assisted Psychotherapy in Patients with Terminal Cancer Cancer patients | 1973 | Experimental study | n = 60 |
Citations in the library
Cited by 9
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- Molecular design of a therapeutic LSD analogue with reduced hallucinogenic potential Proceedings of the National Academy of Sciences April 14, 2025
- Identification of LSD analogs, 1cP-AL-LAD, 1cP-MIPLA, 1V-LSD and LSZ in sheet products. Forensic Toxicology July 1, 2023
- Synthetic Strategies toward Lysergic Acid Diethylamide: Ergoline Synthesis via α-Arylation, Borrowing Hydrogen Alkylation, and C-H Insertion. The Journal of Organic Chemistry October 6, 2023
- Analytical and behavioral characterization of N-ethyl-N-isopropyllysergamide (EIPLA), an isomer of N6 -ethylnorlysergic acid N,N-diethylamide (ETH-LAD). Drug Testing and Analysis February 1, 2024
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