A molecule that can substitute for a normal nucleobase in nucleic acids.
| Member | Definition | Role |
|---|
| 1-methyluracil | A pyrimidone that is uracil with a methyl group substituent at position 1. | 1-methyluracil |
| 1,(n2)-ethenoguanine | A nucleobase analogue obtained by addition of an etheno group across positions 1 and N2 of guanine. | 1,N(2)-ethenoguanine |
| 2-amino-n(6)-hydroxyadenine | A 2,6-diaminopurine that is the N(6)-hydroxy derivative of 2,6-diamino-3H-purine. | 2-amino-6-hydroxyaminopurine |
| 2-aminopurine | The parent compound of the 2-aminopurines, comprising a purine core carrying an amino substituent at the 2-position. | 2-aminopurine |
| 3-methyluracil | A pyrimidone that is uracil with a methyl group at position 3. | 3-methyluracil |
| 5-formylcytosine | A nucleobase analogue that is cytosine in which the hydrogen at position 5 is replaced by a formyl group. | 5-formylcytosine |
| 5-formyluracil | A pyrimidone resulting from the formal oxidation of the alcoholic hydroxy group of 5-hydroxymethyluracil to the corresponding aldehyde. It is a major one-electron photooxidation product of thymine in oligodeoxynucleotides. | 5-formyluracil |
| 5-hydroxymethylcytosine | A nucleobase analogue that is cytosine in which the hydrogen at position 5 is replaced by a hydroxymethyl group. | 5-(hydroxymethyl)cytosine |
| 6-azathymine | A nucleobase analogue that is thymine in which the CH group at position 6 is replaced by nitrogen. | 6-azathymine |
| 6-n-hydroxylaminopurine | A member of the class of 6-aminopurinnes that is adenine in which one of the exocyclic amino hydrogens is replaced by a hydroxy group. | N(6)-hydroxyadenine |
| 8-azaadenine | A triazolopyrimidine that is [1,2,3]triazolo[4,5-d]pyrimidine bearing an amino substituent at position 7. | 8-azaadenine |
| 8-azahypoxanthine | A triazolopyrimidine that consists of 1,4-dihydro-7H-[1,2,3]triazolo[4,5-d]pyrimidine bearing an oxo substituent at position 7. | 8-azahypoxanthine |
| 8-hydroxyadenine | An oxopurine that is adenine bearing a single oxo substituent at position 8. | 8-hydroxyadenine; 8-oxoadenine |
| 8-hydroxyadenine | A nucleobase analogue that is adenine bearing a single hydroxy substituent at position 8. | 8-hydroxyadenine; 8-oxoadenine |
| allopurinol | A bicyclic structure comprising a pyrazole ring fused to a hydroxy-substituted pyrimidine ring. | allopurinol |
| azaguanine | A triazolopyrimidine that consists of 3,6-dihydro-7H-[1,2,3]triazolo[4,5-d]pyrimidine bearing amino and oxo substituents at positions 5 and 7 respectively. | 8-azaguanine |
| azauracil | A 1,2,4-triazine compound having oxo-substituents at the 3- and 5-positions. | 6-azauracil |
| bromouracil | A pyrimidine having keto groups at the 2- and 4-positions and a bromo group at the 5-position. Used mainly as an experimental mutagen. | 5-bromouracil |
| fluorouracil | A nucleobase analogue that is uracil in which the hydrogen at position 5 is replaced by fluorine. It is an antineoplastic agent which acts as an antimetabolite - following conversion to the active deoxynucleotide, it inhibits DNA synthesis (by blocking the conversion of deoxyuridylic acid to thymidylic acid by the cellular enzyme thymidylate synthetase) and so slows tumour growth. | 5-fluorouracil |
| hypoxanthine | A purine nucleobase that consists of purine bearing an oxo substituent at position 6. | hypoxanthine |
| isodialuric acid | A nucleobase analogue that is uracil substituted at positions 5 and 6 by hydroxy groups. | 5,6-dihydroxyuracil |
| n(2),3-ethenoguanine | A nucleobase analogue obtained by addition of an etheno group across positions N2 and 3 of guanine. | N(2),3-ethenoguanine |
| sofosbuvir | A nucleobase analogue that is cytosine in which the hydrogen at position 5 is replaced by a carboxy group. | 5-carboxycytosine |
| thiouracil | A nucleobase analogue that is uracil in which the oxo group at C-2 is replaced by a thioxo group. | thiouracil |