alkaloid

[ al-kuh-loid ]

noun

1. any of a large class of organic, nitrogen-containing ring compounds of vegetable origin and sometimes synthesized, some of which are liquid but most of which are solid, that have a bitter taste, that are usually water-insoluble and alcohol-soluble, that combine with acids without the loss of a water molecule to form water-soluble hydrochlorides, hydrobromides, or the like, and that usually exhibit pharmacological action, as nicotine, morphine, or quinine.

adjective

1. resembling an alkali; alkaline.

alkaloid

/ ˈælkəˌlɔɪd /

noun

1. any of a group of nitrogenous basic compounds found in plants, typically insoluble in water and physiologically active. Common examples are morphine, strychnine, quinine, nicotine, and caffeine

alkaloid

/ ăl′kə-loid′ /

1. Any of a large class of naturally occurring, complex organic compounds that contain nitrogen and have physiological effects on animals, including humans. Most alkaloids occur in plants, although some are produced by fungi and animals. Alkaloids are bases and usually form colorless crystalline solids with a bitter taste. They have a wide range of effects and are used as medicines and poisons. Morphine, quinine, strychnine, codeine, caffeine, cocaine, and nicotine are all alkaloids.

Other Words From

• non·alka·loid noun adjective

Word History and Origins

Origin of alkaloid¹

First recorded in 1825–35; alkal(i) + -oid

Example Sentences

And it would have prohibited ones in which a specific chemical makes up more than 1% of its alkaloid content.

From Los Angeles Times

Tantalosin is a synthetic molecule inspired by alkaloids from the medical plant Cinchona.

From Science Daily

Its complex effects have been tied to mitragynine and other alkaloids — chemical compounds containing nitrogen — that act on systems in the brain and body.

From Los Angeles Times

Pyrrolizidine alkaloids are as bitter and toxic as they are hard to pronounce.

From Science Daily

Poison dart frogs, for example, build up reserves of harmful alkaloids by feeding on toxic insects.

From Science Magazine