Definition of "guanine" [guanine]

• A purine base, C5H5ON5, that is an essential constituent of both RNA and DNA. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The bird droppings, applied in a 90- minute facial, are packed with an enzyme called guanine – an amino acid which heals the skin, experts claim."
• "The bird droppings, applied in a 90-minute facial, are packed with an enzyme called guanine — an amino acid which heals the skin, experts claim."
• "the droppings, which contain an enzyme called guanine"