1	9DG	9-deazaguanine	1.000
2	9HX	9-deazahypoxanthine	0.909
3	GUN	Guanine	0.833
4	8IG	8-iodo-guanine	0.769
5	9MG	9-methylguanine	0.769
6	ANG	8-aminoguanine	0.769
7	AQO	2-aminoquinazolin-4(3h)-one	0.769
8	B55	2-amino-8-sulfanyl-1,9-dihydro-6h-purin-6-one	0.769
9	BRG	8-bromoguanine	0.769
10	MOG	5-amino-2-methyl-6h-oxazolo[5,4-D]pyrimidin-7-one	0.769
11	MY6	2-amino-7-methyl-1,7-dihydro-6h-purin-6-one	0.769
12	OXG	8-oxoguanine	0.769
13	PE0	Pterine	0.769
14	QBK	5-azanyl-[1,3]thiazolo[5,4-D]pyrimidine-2,7-dione	0.769
15	2BP	9h-purin-2-amine	0.750
16	7HP	7-hydroxy-pyrazolo[4,3-D]pyrimidine	0.750
17	9DA	9-deazaadenine	0.750
18	HPA	Hypoxanthine	0.750
19	PPO	3h-pyrazolo[4,3-D]pyrimidin-7-ol	0.750
20	44V	(6s)-2-amino-6-methyl-5,6,7,8-tetrahydropteridin-4(3h)-one	0.714
21	44W	2-amino-6-methyl-7,8-dihydropteridin-4(3h)-one	0.714
22	7PD	2-aminopteridine-4,7(3h,8h)-dione	0.714
23	B60	2-amino-8-methyl-7,8-dihydropteridin-4(3h)-one	0.714
24	B62	(6r)-2-amino-6-methyl-5,6,7,8-tetrahydropteridin-4(3h)-one	0.714
25	DQU	2,6-diamino-3h-quinazolin-4-one	0.714
26	JSO	2-azanyl-6-methyl-3~{H}-pteridin-4-one	0.714
27	MAQ	2-amino-8-methylquinazolin-4(3h)-one	0.714
28	NDM	7,9-dimethylguanine	0.714
29	XHP	2-amino-6-methylidene-6,7-dihydropteridin-4(3h)-one	0.714
30	XTN	2-amino-1,5-dihydropteridine-4,6-dione	0.714