alkaloid

[ al-kuh-loid ]
/ ˈæl kəˌlɔɪd /
Biochemistry, Chemistry, Pharmacology

noun

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

resembling an alkali; alkaline.

Origin of alkaloid

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

OTHER WORDS FROM alkaloid

non·al·ka·loid, noun, adjective

Words nearby alkaloid

alkaline-ash diet, alkaline-earth metal, alkalinity, alkalinuria, alkalize, alkaloid, alkaloidal, alkalosis, alkaluria, alkane, alkane series

Example sentences from the Web for alkaloid

British Dictionary definitions for alkaloid

alkaloid
/ (ˈælkəˌlɔɪd) /

noun

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

Medical definitions for alkaloid

alkaloid
[ ăl′kə-loid′ ]

n.

Any of various organic compounds, such as nicotine and morphine, that have basic chemical properties and that usually contain at least one nitrogen atom in a heterocyclic ring.

Scientific definitions for alkaloid

alkaloid
[ ăl′kə-loid′ ]

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.