Guanine, along with adenine and cytosine, is present in both DNA and RNA, whereas thymine is usually seen only in DNA, … See more

The first isolation of guanine was reported in 1844 by the German chemist Julius Bodo Unger [de] (1819–1885), who obtained it as a mineral formed from the excreta of sea birds, which is known as guano and which was used a… See more

Trace amounts of guanine form by the polymerization of ammonium cyanide (NH 4CN). Two experiments conducted by Levy et al. showed that heating 10 mol·L NH 4CN at 80 °C for 24 hours gave a yield of 0.0007%, … See more

Guanine is not synthesized de novo , instead it's split from the more complex molecule, guanosine, by the enzyme guanosine phosphorylase:
guanosine + phosphate guanine + alpha-D-ribose 1-ph… See more

The word guanine derives from the Spanish loanword guano ('bird/bat droppings'), which itself is from the Quechua word wanu, meaning 'dung'. As the Oxford English Dictionary notes, guanine is "A white amorphou… See more