Pronunciation: (pyoor'ēn, -in), [key]
—n. Chem., Biochem.
1. a white, crystalline compound, C5H4N4, from which is derived a group of compounds including uric acid, xanthine, and caffeine.
2. one of several purine derivatives, esp. the bases adenine and guanine, which are fundamental constituents of nucleic acids.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.