from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. 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.
  • n. Any of several derivatives of this compound.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. Any of a group of alkaloids, that include caffeine, theophylline, and theobromine as well as the parent compound, a precursor of uric acid found in many organs of the body.

from the GNU version of the Collaborative International Dictionary of English

  • A type of purine obtainable as a white microcrystalline powder, C5H4O2N4, present in muscle tissue, in the liver, spleen, pancreas, and other organs, and also in urine (in small quantities) and some urinary calculi, and in the juices of certain plants; -- so called because it leaves a yellow residue when evaporated to dryness with nitric acid. It is also present in guano. Xanthine is closely related to uric acid.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. crystalline oxidation product of the metabolism of nucleoproteins; precursor of uric acid; found in many organs and in urine


Sorry, no etymologies found.


  • 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. Main RSS Feed

  • Theobromine, like caffeine, and also like the asthma drug theophylline, belong to the chemical group known as xanthine alkaloids.

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  • One is completely insoluble in water, which we have termed xanthine, a name which Runge has given to a yellow matter from madder.

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  • In addition, because increasing the excretion of uric acid is additive to the effects of drugs known as xanthine oxidase inhibitors that decrease the production of uric acid, including allopurinol and febuxostat, lesinurad in combination with such drugs has the potential to treat the significant portion of the gout population that is not adequately treated with existing therapies.

  • Even since 1776 when Scheele found uric acid in urinary calculus, several substances closely related to it such as xanthine, adenine and guanine, etc. have been detected in animal secretions.

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  • Carbon isotope ratios for uracil and xanthine of δ13C = + 44.5‰ and + 37.7‰, respectively, indicate a non-terrestrial origin for these compounds.

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  • "Unless you are referring to a yellow nitrogenous compound, xanthine -"

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  • The inhibition was reversed by hypoxanthine, adenine, guanine, and xanthine (28).

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  • The fate of the intermediate oxypurines, hypoxanthine and xanthine, turned out to be a fascinating one.

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  • Xanthine oxidase is responsible not only for the oxidation of 6-MP, but also for the formation of uric acid from hypoxanthine and xanthine (Fig. 4).

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