Examples from the Web for guanine
The cutis contains several kinds of specialized cells in many layers, each filled with minute granules of guanine.
The artificial preparation of theobromine and caffeine from xanthine, and guanine also show clearly their relations.
Adenine and guanine are constituents of all nucleic acids (see below) and, hence, are found in all plant and animal tissues.The Chemistry of Plant Life|Roscoe Wilfred Thatcher
He was afterwards named Biberoci Guahagiona, and the women gave him abundance of guanine and cibe to wear upon his arms.