Trigonelline is an

alkaloid Alkaloids are a broad class of natural product, naturally occurring organic compounds that contain at least one nitrogen atom. Some synthetic compounds of similar structure may also be termed alkaloids. Alkaloids are produced by a large varie ...

with

chemical formula A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as pare ...

. It is a

zwitterion In chemistry, a zwitterion ( ; ), also called an inner salt or dipolar ion, is a molecule that contains an equal number of positively and negatively charged functional groups. : (1,2- dipolar compounds, such as ylides, are sometimes excluded from ...

formed by the

methylation Methylation, in the chemistry, chemical sciences, is the addition of a methyl group on a substrate (chemistry), substrate, or the substitution of an atom (or group) by a methyl group. Methylation is a form of alkylation, with a methyl group replac ...

of the nitrogen atom of

niacin Nicotinic acid, or niacin, is an organic compound and a vitamer of vitamin B3, an essential human nutrient. It is produced by plants and animals from the amino acid tryptophan. Nicotinic acid is also a prescription medication. Amounts f ...

(vitamin B₃). Trigonelline is a product of niacin metabolism that is excreted in the urine of mammals. Trigonelline occurs in many plants. It has been isolated from the Japanese

radish The radish (''Raphanus sativus'') is a flowering plant in the mustard family, Brassicaceae. Its large taproot is commonly used as a root vegetable, although the entire plant is edible and its leaves are sometimes used as a leaf vegetable. Origina ...

(''Raphanus sativus'' cv. Sakurajima Daikon),

fenugreek Fenugreek (; ''Trigonella foenum-graecum'') is an annual plant in the family Fabaceae, with leaves consisting of three small Glossary_of_leaf_morphology#Leaf_and_leaflet_shapes, obovate to oblong leaflets. It is cultivated worldwide as a semiar ...

seeds (''Trigonella foenum-graecum'', hence the name), garden peas, hemp seed, oats, potatoes, ''

Stachys ''Stachys'' is a genus of plants, one of the largest in the mint family Lamiaceae.Harley, R. M., et al. 2004. "Labiatae". pages 167–275. In: Kubitzki, K. (editor) and J. W. Kadereit (volume editor). ''The Families and Genera of Vascular Plants ...

'' species,

dahlia ''Dahlia'' ( , ) is a genus of bushy, tuberous, herbaceous perennial plants native to Mexico and Central America. Dahlias are members of the Asteraceae (synonym name: Compositae) family of dicotyledonous plants, its relatives include the sun ...

, ''

Strophanthus ''Strophanthus'' is a genus of flowering plants in the family Apocynaceae, first described as a genus in 1802. It is native primarily to tropical Africa, extending to South Africa, with a few species in Asia from southern India to New Guinea and ...

'' species, and '' Dichapetalum cymosum''. Trigonelline is also found in

coffee Coffee is a beverage brewed from roasted, ground coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulating effect on humans, primarily due to its caffeine content, but decaffeinated coffee is also commercially a ...

. Higher levels of trigonelline are found in arabica coffee. Holtz, Kutscher, and Theilmann have recorded its presence in a number of animals.

Chemistry

Trigonelline crystallizes as a monohydrate from

alcohol Alcohol may refer to: Common uses * Alcohol (chemistry), a class of compounds * Ethanol, one of several alcohols, commonly known as alcohol in everyday life ** Alcohol (drug), intoxicant found in alcoholic beverages ** Alcoholic beverage, an alco ...

in hygroscopic prisms (m.p. 130 °C or 218 °C 'dry, dec.''. It is readily soluble in water or warm alcohol, less so in cold alcohol, and slightly so in

chloroform Chloroform, or trichloromethane (often abbreviated as TCM), is an organochloride with the formula and a common solvent. It is a volatile, colorless, sweet-smelling, dense liquid produced on a large scale as a precursor to refrigerants and po ...

ether In organic chemistry, ethers are a class of compounds that contain an ether group, a single oxygen atom bonded to two separate carbon atoms, each part of an organyl group (e.g., alkyl or aryl). They have the general formula , where R and R� ...

. The salts crystallize well, the monohydrochloride, in leaflets, sparingly soluble in dry alcohol. The picrate forms shining prisms (m.p. 198−200 °C) soluble in water but sparingly soluble in dry alcohol or ether. The alkaloid forms several aurichlorides: the normal salt, B•HCl•AuCl₃, is precipitated when excess of gold chloride is added to the hydrochloride, and, after crystallization from dilute hydrochloric acid containing some gold chloride, has m.p. 198 °C. Crystallized from water or very dilute hydrochloric acid, slender needles of B₄•3 HAuCl₄ (m.p. 186 °C) are obtained. When trigonelline is heated in closed tubes with

barium hydroxide Barium hydroxide is a chemical compound with the chemical formula Ba(OH)2. The monohydrate (''x'' = 1), known as baryta or baryta-water, is one of the principal compounds of barium. This white granular monohydrate is the usual commercial form. ...

at 120 °C, it gives rise to

methylamine Methylamine, also known as methanamine, is an organic compound with a formula of . This colorless gas is a derivative of ammonia, but with one hydrogen atom being replaced by a methyl group. It is the simplest primary amine. Methylamine is sold ...

, and, if treated similarly with hydrochloric acid at 260 °C creates

chloromethane Chloromethane, also called methyl chloride, Refrigerant-40, R-40 or HCC 40, is an organic compound with the chemical formula . One of the haloalkanes, it is a colorless, sweet-smelling, flammable gas. Methyl chloride is a crucial reagent in indu ...

and

nicotinic acid Nicotinic acid, or niacin, is an organic compound and a vitamer of vitamin B3, an essential human nutrient. It is produced by plants and animals from the amino acid tryptophan. Nicotinic acid is also a prescription medication. Amounts f ...

(a form of vitamin B₃). Trigonelline is a methyl

betaine A betaine () in chemistry is any neutral chemical compound with a positively charged cationic functional group that bears no hydrogen atom, such as a Quaternary ammonium cation, quaternary ammonium or phosphonium cation (generally: Onium compou ...

of nicotinic acid.

References

{{reflist Alkaloids Quaternary ammonium compounds Nicotinates Coffee chemistry Zwitterions