Nucleotide, a compound consisting of a mixture of a purine base or a pyrimidine base, ribose or deoxyribose, and phosphoric acid. Also known as nuclear niacin. The nucleotide and the desalting nucleotide are amphiphilic compounds containing a base capable of forming a positive ion and a phosphate group capable of forming an anion, and thus can be separated and purified by using a cation exchange resin and an anion exchange resin.