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| Names | |
|---|---|
| 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 | |
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3D model (JSmol) | |
| ChEBI | |
| ChemSpider |
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| ECHA InfoCard | 100.001.302 |
| UNII | |
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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 theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Lysergic acid, also known asD-lysergic acid and(+)-lysergic acid, is a precursor for a wide range ofergolinealkaloids that are produced by theergot fungus and found in the seeds ofArgyreia nervosa (Hawaiian baby woodrose), andIpomoea species (morning glories,ololiuhqui,tlitliltzin).
Amides of lysergic acid,lysergamides, are widely used aspharmaceuticals and aspsychedelic drugs, e.g.lysergic acid diethylamide (LSD). Lysergic acid is listed as a Table I precursor under theUnited Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances.[3]
The name "lysergic acid" comes from the fact that it is acarboxylic acid, and it was first made byhydrolysis of variousergot alkaloids.[4]
Lysergic acid failed to produceLSD-likeelectroencephalogram (EEG) changes in rabbits.[5]
Lysergic acid is generally produced byhydrolysis[6] of natural lysergamides, but can also be synthesized in the laboratory by a complextotal synthesis, for example byRobert Burns Woodward's team in 1956.[7] Anenantioselective total synthesis based on apalladium-catalyzed dominocyclization 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.
The biosynthetic route is based on thealkylation of the amino acidtryptophan withdimethylallyl diphosphate (isoprene derived from 3R-mevalonic acid) giving 4-dimethylallyl-L-tryptophan which isN-methylated withS-adenosyl-L-methionine. Oxidative ring closure followed by decarboxylation, reduction, cyclization, oxidation, and allylicisomerization yieldsD-(+)-lysergic acid.[4] The biosynthetic pathway has been reconsituted in transgenic baker's yeast.[9]
Lysergic acid is achiral compound with twostereocenters. Theisomer with inverted configuration at carbon atom 8 close to thecarboxyl group is calledisolysergic acid. Inversion at carbon 5 close to thenitrogen atom leads toL-lysergic acid andL-isolysergic acid, respectively.
In the United States, Lysergic acid and Lysergic acid amide are Schedule III substances.[10]
EEG studies. Synthetic and biosynthetic metabolites of LSD were injected intravenously into conscious restrained male chinchilla rabbits. With LSD itself, de-ethyl-LSD, 12-hydroxy-LSD, 12-methoxy-LSD, 13-hydroxy-LSD, 13-methoxy-LSD and 13-hydroxy-LSD glucuronide, a persistent alerting EEG trace was seen as indicated by an increase in frequency and decrease in amplitude of the waveform. No changes were observed after administration of lysergic acid, di-LSD-disulphide [10], nor-LSD, 14-hydroxy-LSD-glucuronide, 14-methoxy-LSD, lumi-LSD or the metabolic 2-oxo-LSD. [...] Preliminary studies have indicated that some of the metabolites of LSD, as well as the drug itself. produce an activation of the EEG of the conscious rabbit suggesting they may have central activity. These findings will be published elsewhere.
