Definition of "xanthine" []

  • A yellowish-white, crystalline purine base, C5H4N4O2, that is a precursor of uric acid and is found in blood, urine, muscle tissue, and certain plants. (noun)
  • Any of several derivatives of this compound. (noun)
  • A crystalline compound related in structure to uric acid and found in urine, blood, certain plants, and certain animal tissues. Formula: C5H4N4O2 (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

  • Any substituted derivative of xanthine, esp one of the three pharmacologically active methylated xanthines, caffeine, theophylline, or theobromine, which act as stimulants and diuretics (noun) (c) HarperCollins Publishers Ltd 2016

Use "xanthine" in a sentence
  • "Milk fat contains an enzyme called xanthine oxidase (XO), some of which survives the pasteurization process and, thanks to homogenization, is now able to pass through the gut wall into the bloodstream intact where it creates havoc by attacking plasmalogen within artery walls."
  • "Theobromine, like caffeine, and also like the asthma drug theophylline, belong to the chemical group known as xanthine alkaloids."
  • "One is completely insoluble in water, which we have termed xanthine, a name which Runge has given to a yellow matter from madder."