Anhalotine

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Anhalotine
Anhalotine.svg
Names
IUPAC name
6,7-dimethoxy-2,2-dimethyl-8-hydroxy-1,2,3,4-tetrahydroisoquinolin-2-ium iodide
Other names
Anhalidine methiodide; anhalotine iodide
Identifiers
3D model (JSmol)
  • InChI=1S/C13H20NO3.I/c1-14(2)6-5-10-8(13(14)7-11(10)15-3)9(16-4)12(17)10;/h7,9,12,17H,5-6H2,1-4H3;/q+1;-1
  • [I-].COc1c(OC)c(O)c2c(c1)CC[N+](C)(C)C2
Properties
C13H20INO3
Molar mass 365.21
AppearanceColorless crystals
Melting point 219 220 °C
Soluble in water and ethanol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Anhalotine is a tetrahydroisoquinoline alkaloid found in the cactus Lophophora williamsii (peyote). [1] It is a quaternary ammonium compound, specifically the methiodide of the secondary alkaloid anhalidine. [1] Anhalotine occurs in trace amounts alongside other peyote alkaloids such as mescaline, anhalonidine, pellotine, and anhalonine. As a quaternary salt, it is not psychoactive. [2]

Contents

History

Anhalotine was first isolated from peyote in 1968 by Govind J. Kapadia, Narendra J. Shah, and Theodore B. Zalucky at the University of Michigan. [1] Using thin-layer chromatography, ultraviolet spectroscopy, and infrared spectroscopy, they identified it as the methiodide of anhalidine, yielding 7 mg from 2.3 kg of dried peyote buttons (0.0003% dry weight). [1]

Natural occurrence

Anhalotine is a minor alkaloid in Lophophora williamsii, present at concentrations of approximately 0.0003% by dry weight. [1] It has also been reported in trace amounts in other Lophophora species, such as L. diffusa , and potentially in related cacti like Aztekium ritteri and Pelecyphora aselliformis via its parent compound anhalidine. [2] Concentrations vary depending on factors such as plant age, habitat, and analytical methods.

Chemistry

Structure

Anhalotine is a quaternary tetrahydroisoquinoline alkaloid with the chemical formula C13H20NO3+ (cation) and C13H20INO3 (iodide salt). It consists of a 1,2,3,4-tetrahydroisoquinoline core substituted with methoxy groups at positions 6 and 7, a hydroxy group at position 8, and a 2,2-dimethyl-2-ium iodide at the nitrogen (position 2). [1] [3] [2] It is structurally related to anhalidine, from which it differs only by the additional methyl group on the nitrogen, forming the quaternary salt. [1]

Biosynthesis

Anhalotine shares the biosynthetic pathway common to peyote's tetrahydroisoquinoline alkaloids, beginning with the amino acid L-tyrosine. Tyrosine undergoes decarboxylation to tyramine, followed by meta-hydroxylation, para-O-methylation, and cyclization via a Pictet-Spengler reaction with formaldehyde (derived from S-adenosylmethionine). This yields anhalidine, which is then N,N-dimethylated to form the quaternary anhalotine. [4]

Pharmacology

As a quaternary ammonium compound, anhalotine is highly polar and poorly crosses the blood-brain barrier, suggesting minimal central nervous system activity. [2] No dedicated pharmacological studies or human/animal bioassays have been conducted on anhalotine, likely due to its trace occurrence and the challenges of isolating sufficient quantities. [2] It is not considered to contribute significantly to the psychoactive effects of peyote, which are primarily attributed to mescaline.

Anhalotine is not specifically scheduled under international conventions such as the Convention on Psychotropic Substances or in major national drug laws, including the U.S. Controlled Substances Act. However, it is a constituent of Lophophora williamsii, which is classified as a Schedule I controlled substance in the United States owing to its mescaline content. Exemptions exist for traditional religious use by members of the Native American Church. [5]

See also

References

  1. 1 2 3 4 5 6 7 Kapadia, G. J.; Shah, N. J.; Zalucky, T. B. (1968). "Peyote alkaloids. II. Anhalotine, lophotine, and peyotine, the quaternary alkaloids of Lophophora williamsii". Journal of Pharmaceutical Sciences. PMID   5641668.
  2. 1 2 3 4 5 Trout, Keeper (2013). Trout's Notes on the Cactus Alkaloids: Nomenclature, Physical Properties, Pharmacology, and Occurrences (PDF) (4th ed.). Mydriatic Productions/Better Days Publishing. p. 188.
  3. Southon, I. W.; Buckingham, J. (1989). Dictionary of Alkaloids. Vol. 2. Chapman and Hall. pp. T-00108. ISBN   0-412-24910-3.
  4. Lundström, J. (1971). "Biosynthesis of mescaline and tetrahydroisoquinoline alkaloids in Lophophora williamsii (Lem.) Coult". Acta Pharmaceutica Suecica. 8 (3): 261–274. PMID   5560271.
  5. "Drug Scheduling". U.S. Drug Enforcement Administration. Retrieved 2025-11-05.