Lysergic acid


Lysergic acid, also known as -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, and Ipomoea species.
Amides of lysergic acid, lysergamides, are widely used as pharmaceuticals and as psychedelic drugs, e.g. lysergic acid diethylamide. Lysergic acid is listed as a Table I precursor under the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances.
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.

Pharmacology

Lysergic acid failed to produce LSD-like electroencephalogram changes in rabbits.

Chemistry

Synthesis

Laboratory

Lysergic acid is generally produced by hydrolysis 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. An enantioselective total synthesis based on a palladium-catalyzed domino cyclization reaction has been described in 2011 by Fujii and Ohno. Lysergic acid monohydrate crystallizes in very thin hexagonal leaflets when recrystallized from water. Lysergic acid monohydrate, when dried forms anhydrous lysergic acid.

Biosynthesis

The biosynthetic route is based on the alkylation of the amino acid tryptophan with dimethylallyl diphosphate giving 4-dimethylallyl--tryptophan which is N-methylated with S-adenosyl--methionine. Oxidative ring closure followed by decarboxylation, reduction, cyclization, oxidation, and allylic isomerization yields --lysergic acid. The biosynthetic pathway has been reconsituted in transgenic baker's yeast.

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 -lysergic acid and -isolysergic acid, respectively.

Society and culture

Legal status

Canada

Lysergic acid is a controlled substance in Canada.

United States

In the United States, lysergic acid and lysergic acid amide are Schedule III substances.