Lysergic acid
Precursor for a range of ergoline alkaloids produced by the ergot fungus
From Wikipedia, the free encyclopedia
Lysergic acid, also known as D-lysergic acid and (+)-lysergic acid, is a precursor for a wide range of ergoline alkaloids that are produced by the ergot fungus and found in the seeds of Argyreia nervosa (Hawaiian baby woodrose), and Ipomoea species (morning glories, ololiuhqui, tlitliltzin).
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| Names | |
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| IUPAC name
6-Methyl-9,10-didehydroergoline-8β-carboxylic acid | |
| Systematic IUPAC name
(5R,8R)-7-Methyl-4,6,6a,7,8,9-hexahydroindolo[4,3-fg]quinoline-9-carboxylic acid | |
| Identifiers | |
3D model (JSmol) |
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| ChEBI | |
| ChemSpider | |
| ECHA InfoCard | 100.001.302 |
PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| C16H16N2O2 | |
| Molar mass | 268.316 g·mol−1 |
| Melting point | 238 to 240 °C (460 to 464 °F; 511 to 513 K) |
| Acidity (pKa) | pKa1 = 7.80, pKa2 = 3.30 [1] |
| Legal status | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Amides of lysergic acid, lysergamides, are widely used as pharmaceuticals and as psychedelic drugs, e.g. lysergic acid diethylamide (LSD). Lysergic acid is listed as a Table I precursor under the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances.[3]
The name "lysergic acid" comes from the fact that it is a carboxylic acid, and it was first made by hydrolysis of various ergot alkaloids.[4]
Pharmacology
Lysergic acid failed to produce LSD-like electroencephalogram (EEG) changes in rabbits.[5]
Chemistry
Synthesis
Laboratory
Lysergic acid is generally produced by hydrolysis[6] of natural lysergamides, but can also be synthesized in the laboratory by a complex total synthesis, for example by Robert Burns Woodward's team in 1956.[7] An enantioselective total synthesis based on a palladium-catalyzed domino cyclization reaction has been described in 2011 by Fujii and Ohno.[8] Lysergic acid monohydrate crystallizes in very thin hexagonal leaflets when recrystallized from water. Lysergic acid monohydrate, when dried (140 °C at 2 mmHg or 270 Pa) forms anhydrous lysergic acid.
Biosynthesis
The biosynthetic route is based on the alkylation of the amino acid tryptophan with dimethylallyl diphosphate (isoprene derived from 3R-mevalonic acid) giving 4-dimethylallyl-L-tryptophan which is N-methylated with S-adenosyl-L-methionine. Oxidative ring closure followed by decarboxylation, reduction, cyclization, oxidation, and allylic isomerization yields D-(+)-lysergic acid.[4] The biosynthetic pathway has been reconsituted in transgenic baker's yeast.[9]
Isomers
Lysergic acid is a chiral compound with two stereocenters. The isomer with inverted configuration at carbon atom 8 close to the carboxyl group is called isolysergic acid. Inversion at carbon 5 close to the nitrogen atom leads to L-lysergic acid and L-isolysergic acid, respectively.
