• synonyms


[zan-theen, -thin]
noun Biochemistry, Chemistry.
  1. a crystalline, nitrogenous compound, C5H4N4O2, related to uric acid, occurring in urine, blood, and certain animal and vegetable tissues.
  2. any derivative of this compound.
Show More

Origin of xanthine

From French, dating back to 1855–60; see origin at xantho-, -ine2
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for xanthine

Historical Examples

  • The artificial preparation of theobromine and caffeine from xanthine, and guanine also show clearly their relations.

    Scientific American Supplement, No. 415, December 15, 1883


  • This precipitate we treat with cold alcohol, which leaves behind the fatty acids, and dissolves the xanthine.

    The Art of Perfumery

    G. W. Septimus Piesse

  • It comprises the xanthine group and the uric acid group of bodies.

British Dictionary definitions for xanthine


  1. a crystalline compound related in structure to uric acid and found in urine, blood, certain plants, and certain animal tissues. Formula: C 5 H 4 N 4 O 2
  2. any substituted derivative of xanthine, esp one of the three pharmacologically active methylated xanthines, caffeine, theophylline, or theobromine, which act as stimulants and diuretics
Show More
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

xanthine in Medicine


(zănthēn′, -thĭn)
  1. A yellowish-white crystalline purine base that is a precursor of uric acid and is found in blood, urine, and muscle tissue.
  2. Any of several derivatives of this compound.
Show More
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

xanthine in Science


[zănthēn′, -thĭn]
  1. Any of various purines having two oxygen atoms attached to the six-member ring of carbon and nitrogen atoms. Xanthines include caffeine, theophylline (a toxic alkaloid found in tea leaves), and theobromine (a toxic alkaloid found in cocoa).
  2. The simplest of this class of compounds, forming yellowish-white crystals. It is produced in the body as an intermediate stage in the breakdown of purines to uric acid. It is also found in blood and in certain plants. Chemical formula: C5H4N4O2.
  3. Any of several derivatives of this compound.
Show More
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.