alkaloid

[al-kuh-loid] Biochemistry, Chemistry, Pharmacology.
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
2.
resembling an alkali; alkaline.

Origin:
1825–35; alkal(i) + -oid

nonalkaloid, noun, adjective
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To alkaloid
Collins
World English Dictionary
alkaloid (ˈælkəˌlɔɪd)
 
n
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

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
Etymonline
Word Origin & History

alkaloid
1831 (n.), 1859 (adj.), from alkali (q.v.) + -oid.
Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
American Heritage
Medical Dictionary

alkaloid al·ka·loid (āl'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.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
American Heritage
Science Dictionary
alkaloid   (āl'kə-loid')  Pronunciation Key 
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.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Example sentences
In some cases the bitter taste is accompanied by alkaloid toxicity.
It's been seven hours since the leaves were picked, and they're already
  secreting the raw alkaloid that gives cocaine its kick.
You're breeding rice plants that produce more alkaloid toxins in their leaves.
The stimulating property of coffee is due to the alkaloid caffeine, together
  with an essential oil.
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature
FAVORITES
RECENT

;