The Nucleic Acid Modification Database

ID	Symbol	Common_Name	Chemical_Formula	Nucleoside_Mass	Description
1	1mA	1-methyladenine	C6H7N5	149.16	Adenine substituted with a methyl group at position N-1.
2	3mA	3-methyladenine	C6H7N5	149.16	A methyladenine that is adenine substituted with a methyl group at position N-3.
3	4mA	4-methyladenine	C6H9N5	151.17	A methyladenine in which the methyl substituent is located at position 4.
4	6mA	6-methyladenine	C6H7N5	149.16	A methyladenine that is 9H-purin-6-amine substituted by a methyl group at the amino nitrogen.
5	7mA	7-methyladenine	C6H7N5	149.16	Adenine substituted with a methyl group at position N-7.
6	9mA	9-methyladenine	C6H7N5	149.16	Adenine substituted with a methyl group at position N-9.
7	6hmA	6-hydroxymethyladenine	C6H7N5O	165.16	A 6-alkylaminopurine that is adenine where one of the hydrogens of the amino group is replaced by a hydroxymethyl group.
8	HAP	6-hydroxyaminopurine	C5H5N5O	151.13	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.
9	m2A	2-aminoadenine	C5H6N6	150.15	A member of the class of 2,6-diaminopurines that is 9H-purine in which the hydrogens at positions 2 and 6 are replaced by amino groups.
10	AHAP	2-amino-6-hydroxyaminopurine	C5H6N6O	166.14	A 2,6-diaminopurine that is the N(6)-hydroxy derivative of 2,6-diamino-3H-purine.
11	6-DMA	N6,N6-dimethyladenine	C7H9N5	163.18	A tertiary amine that is adenine substituted at N-6 by geminal methyl groups.
12	ncm6A	N6-carbamoylmethyladenine	C7H8N6O	192.18	A nucleobase analogue that is adenine in which one of the exocyclic amino hydrogens is replaced by a carbamoylmethyl group.
13	ɛA	1,N6-ethenoadenine	C7H6N5+	160.16