Adenine and guanine both belong to the purine bases.
Tips
usage
In health talk 嘌呤 is about diet: the body turns purines into 尿酸 'uric acid', so people with 痛风 'gout' avoid seafood, organ meat and beer. In biology it pairs with 嘧啶 'pyrimidine', the other family of DNA bases.
memory
Both characters only spell the sound: 嘌 for 'pu-' and 呤 for '-rine'. The mouth radical 口 on the left is the usual mark of a character used for its sound.
