Share this entry

Share this page

xanthine

Syllabification: xan·thine
Pronunciation: /ˈzanˌTHēn, -THin
 
/

Definition of xanthine in English:

noun

Biochemistry
1A crystalline compound that is found in blood and urine and is an intermediate in the metabolic breakdown of nucleic acids to uric acid.
Example sentences
  • Xanthine oxidase catalyses the oxidation of xanthine and hypoxanthine to uric acid and is a well-known producer of superoxide radicals.
  • It appears that the purine metabolic system in humans has found a way to avoid the overproduction of uric acid by downregulating the Xor gene expression, the product converting hypoxanthine to xanthine and further xanthine to uric acid.
  • Xanthine oxidase activity was evaluated by the spectrophotometric measurement of the formation of uric acid from xanthine.
1.1Any of the derivatives of this, including caffeine and related alkaloids.
Example sentences
  • Methyl xanthines (caffeine, theophylline and theobromine) are found in seeds and leaves of a variety of unrelated plant species, including coffee, tea, cocoa, cola and mate.
  • Ephedrine and the xanthines, such as caffeine and theophylline, increase metabolic rate.
  • The main components of this tea are natural xanthines such as caffeine, theobromine, theophylline and tanni.

Origin

mid 19th century: from xanthic (from Greek xanthos 'yellow' + -ic) + -ine4.

Definition of xanthine in:

Share this entry

Share this page

 

What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.

Get more from Oxford Dictionaries

Subscribe to remove adverts and access premium resources

Word of the day reciprocity
Pronunciation: ˌrɛsɪˈprɒsɪti
noun
exchanging things with others for mutual benefit…