xanthine

views updated May 23 2018

xanthine A purine, intermediate in the metabolism of adenine and guanine to uric acid. Caffeine (in coffee and tea) is 1,3,7‐trimethylxanthine; theophylline (in tea) is 1,3‐dimethylxanthine; theobromine (in cocoa) is 3,7‐dimethylxanthine.

xanthine

views updated May 29 2018

xanthine (zanth-een) n. a nitrogenous breakdown product of the purines adenosine and guanine. Xanthine is an intermediate product of the breakdown of nucleic acids to uric acid.