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

An alkaloid discovered by Brandes in atropa belladonna or deadly nightshade.

From Project Gutenberg

Alkaloid, al′ka-loid, n. a vegetable principle possessing in some degree alkaline properties.

From Project Gutenberg

Apomorphia, a-po-morf′i-a, n. an alkaloid prepared from morphia by heating hydrochloric acid—a rapid and powerful emetic.

From Project Gutenberg

Alkaloid from Aconite, prepared according to process of Duquesnel.

From Project Gutenberg

It is the alkaloid of aconite, and generally fatal in its results.

From Project Gutenberg