January 25, 2021
Consume me at your peril.
What molecule am I?

Arecoline is an alkaloid ester found in the seeds of the betel nut palm, which is also called areca palm from its scientific name, Areca catechu. The term “betel nut” is a bit confusing because South and Southeast Asians often chew it along with betel leaf from the vine of the same name (Piper betle). The two plants are not biologically related.

Arecoline has been known since 1891, when German pharmacist E. Jahns isolated it from A. catechu seeds. The first synthesis was reported by Fritz Chemnitius1 at Jena University (Germany) in 1926. It is a moderately strong base, with a pKb value of 6.8. It is miscible with water and most organic solvents. The carboxylic acid corresponding to the arecoline ester is called arecaidine; it also exists in betel nuts.

People consume betel nuts because they provide a “high” similar to that caused by nicotine. Arecoline, however, acts on different receptors than does nicotine: muscarinic (rather than nicotinic) acetylcholine receptors, especially M4, which may be the cause of its effects on the parasympathetic nervous system. Similarly to nicotine, arecoline is addictive. Chewing betel nuts is also dangerous because they contain ingredients that can cause cancers of the mouth and the esophagus.

1. Chemnitius is also known for his 1932 article about chemistry at Jena University from 1629 to 1921.

Arecoline hazard information

Hazard class* Hazard statement
Acute toxicity, oral, category 4 H302—Harmful if swallowed Chemical Safety Warning

*Globally Harmonized System of Classification and Labeling of Chemicals. Explanation of pictograms. 

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Arecoline fast facts

CAS Reg. No. 63-75-2
3-Pyridinecarboxylic acid, 1,2,5,6-tetrahydro-1-methyl, methyl ester
Empirical formula C8H13NO2
Molar mass 155.19 g/mol
Appearance Colorless oily liquid
Melting point 27 ºC
Boiling point 209 ºC
Water solubility Miscible
Chemical Abstract Service - a division of ACS

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