Bitter compounds

Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class and is the most commonly consumed psychoactive substance globally. It is mainly used for its eugeroic (wakefulness promoting), ergogenic (physical performance-enhancing), or nootropic (cognitive-enhancing) properties; it is also used recreationally or in social settings. Caffeine acts by blocking the binding of adenosine at a number of adenosine receptor types, inhibiting the centrally depressant effects of adenosine and enhancing the release of acetylcholine. Caffeine has a three-dimensional structure similar to

Quinine is a medication used to treat malaria and babesiosis. This includes the treatment of malaria due to Plasmodium falciparum that is resistant to chloroquine when artesunate is not available. While sometimes used for nocturnal leg cramps, quinine is not recommended for this purpose due to the risk of serious side effects. It can be taken by mouth or intravenously. Malaria resistance to quinine occurs in certain areas of the world. Quinine is also used as an ingredient in tonic water and other beverages to impart a bitter taste.

Theobromine, also known as xantheose, is the principal alkaloid of Theobroma cacao (cacao plant). Theobromine is slightly water-soluble (330 mg/L) with a bitter taste. In industry, theobromine is used as an additive and precursor to some cosmetics. It is found in chocolate and several other foods, including tea (Camellia sinensis), some American hollies (yaupon and guayusa) and the kola nut. It is a white or colourless solid, but commercial samples can appear yellowish.

thumb|right|upright|Theophylline extended-release tablets in Japan Theophylline, also known as 1,3-dimethylxanthine, is a drug that inhibits phosphodiesterase and blocks adenosine receptors. It is used to treat chronic obstructive pulmonary disease (COPD) and asthma. Its pharmacology is similar to other methylxanthine drugs (e.g., theobromine and caffeine). Trace amounts of theophylline are naturally present in tea, coffee, chocolate, yerba mate, guarana, and kola nut.

Papaverine (Latin papaver, "poppy") is an opium alkaloid antispasmodic drug, used primarily in the treatment of visceral spasms and vasospasms (especially those involving the intestines, heart, or brain), occasionally in the treatment of erectile dysfunction and acute mesenteric ischemia. While it is found in the opium poppy, papaverine differs in both structure and pharmacological action from the analgesic morphine and its derivatives (such as codeine).

Quinidine is a class IA antiarrhythmic agent used to treat heart rhythm disturbances. It is a diastereomer of antimalarial agent quinine, originally derived from the bark of the cinchona tree. The drug causes increased action potential duration, as well as a prolonged QT interval. As of 2019, its IV formulation is no longer being manufactured for use in the United States.

Salicin is an alcoholic β-glucoside. Salicin is produced in (and named after) willow (Salix) bark. It is a biosynthetic precursor to salicylaldehyde.

Brucine is an alkaloid closely related to strychnine, most commonly found in the Strychnos nux-vomica tree. Brucine poisoning is rare, since it is usually ingested with strychnine, and strychnine is more toxic than brucine. In chemical synthesis, it can be used as a tool for stereospecific chemical syntheses.

Denatonium is an organic ion and one of the bitterest chemical compounds known, with bitterness thresholds of 0.05 ppm for the benzoate and 0.01 ppm for the saccharinate. Commercially, it is usually available in salts such as denatonium benzoate (under trade names such as Denatrol, BITTERANT-b, BITTER+PLUS, Bitrex, Bitrix, Toxishield and Aversion) or as denatonium saccharinate (BITTERANT-s).

Propylthiouracil (PTU) is a medication used to treat hyperthyroidism. This includes hyperthyroidism due to Graves' disease and toxic multinodular goiter. In a thyrotoxic crisis it is generally more effective than methimazole. Otherwise it is typically only used when methimazole, surgery, and radioactive iodine is not possible. It is taken by mouth.

Hesperidin is a flavanone glycoside found in citrus fruits. Its aglycone is hesperetin. Its name is derived from the word "hesperidium", for fruit produced by citrus trees.

Phenylthiocarbamide (PTC), also known as phenylthiourea (PTU), is an organosulfur thiourea containing a phenyl ring.

Naringin is a flavanone-7-O-glycoside between the flavanone naringenin and the disaccharide neohesperidose. The flavonoid naringin occurs naturally in citrus fruits, especially in grapefruit, where naringin is responsible for the fruit's bitter taste. In commercial grapefruit juice production, the enzyme naringinase can be used to remove the bitterness (debittering) created by naringin. In humans naringin is metabolized to the aglycone naringenin (not bitter) by naringinase present in the gut.

crystalline material

Absinthin is a naturally produced triterpene lactone from the plant Artemisia absinthium (Wormwood). It constitutes one of the most bitter chemical agents responsible for absinthe's distinct taste. The compound shows biological activity and has shown promise as an anti-inflammatory agent, and should not be confused with thujone, a neurotoxin also found in Artemisia absinthium.

Aloin, also known as barbaloin, is a bitter, yellow-brown colored compound noted in the exudate of at least 68 Aloe species at levels from 0.1 to 6.6% of leaf dry weight (making between 3% and 35% of the total exudate), and in another 17 species at indeterminate levels [Reynolds, 1995b]. It is used as a stimulant-laxative, treating constipation by inducing bowel movements. The compound is present in what is commonly referred to as the aloe latex that exudes from cells adjacent to the vascular bundles, found under the rind of the leaf and in between it and the gel.

Amarogentin is a chemical compound found in gentian

Quassin is a white, bitter, crystalline substance that is the prototypical example of the family of quassinoids. It can be extracted from the quassia tree, from which it gets its name. It was first isolated in 1937, and its chemical structure was elucidated in 1961.

Humulone (α-lupulic acid), a vinylogous type of organic acid, is a bitter-tasting chemical compound found in the resin of mature hops (Humulus lupulus). Humulone is a prevalent member of the class of compounds known as alpha acids, which collectively give hopped beer its characteristic bitter flavor.

Eugenin is a chromone derivative, a phenolic compound found in cloves. It is also present in carrots.

Andrographolide is a labdane diterpenoid that has been isolated from the stem and leaves of Andrographis paniculata. Andrographolide is an extremely bitter substance.

group of chemical compounds

Isohumulones are chemical compounds that contribute to the bitter taste of beer and are in the class of compounds known as iso-alpha acids. They are found in hops.

chemical compound

6-Methoxymellein is a dihydroisocoumarin, a phenolic compound found in carrots and carrot purées. It is responsible for bitterness in carrots. It is a phytoalexin, induced in carrot slices by UV-C, that allows resistance to Botrytis cinerea and other microorganisms.