/pyoor"een, -in/ , n. Chem., Biochem.
1. a white, crystalline compound, C 5 H 4 N 4 , 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.
[ 1895-1900; Purin. See PURE, URIC, -INE 2 ]