1	OXG	8-oxoguanine	1.000
2	GUN	Guanine	0.917
3	8IG	8-iodo-guanine	0.846
4	9MG	9-methylguanine	0.846
5	ANG	8-aminoguanine	0.846
6	B55	2-amino-8-sulfanyl-1,9-dihydro-6h-purin-6-one	0.846
7	BRG	8-bromoguanine	0.846
8	MY6	2-amino-7-methyl-1,7-dihydro-6h-purin-6-one	0.846
9	QBK	5-azanyl-[1,3]thiazolo[5,4-D]pyrimidine-2,7-dione	0.846
10	URC	Uric acid	0.846
11	2BP	9h-purin-2-amine	0.833
12	HPA	Hypoxanthine	0.833
13	7PD	2-aminopteridine-4,7(3h,8h)-dione	0.786
14	MUA	9-methyl uric acid	0.786
15	NDM	7,9-dimethylguanine	0.786
16	XTN	2-amino-1,5-dihydropteridine-4,6-dione	0.786
17	2ON	2-sulfanyl-1,9-dihydro-6h-purin-6-one	0.769
18	6AP	9h-purine-2,6-diamine	0.769
19	6GU	6-chloroguanine	0.769
20	7DG	7-deazaguanine	0.769
21	9DG	9-deazaguanine	0.769
22	AZG	5-amino-1h-[1,2,3]triazolo[4,5-D]pyrimidin-7-ol	0.769
23	BOA	2-bromo-6-hydroxy-purine	0.769
24	DX4	2-amino-1,9-dihydro-6h-purine-6-thione	0.769
25	HH5	6-iodanyl-7~{H}-purin-2-amine	0.769
26	QY8	2-amino-3h,4h,7h-pyrrolo[2,3-D]pyrimidin-4-one	0.769
27	XAN	Xanthine	0.769
28	IUP	5-(hydro)peroxoisourate	0.733
29	29H	2-aminopyrimido[4,5-D]pyrimidin-4(3h)-one	0.714
30	5JL	2,8-dithioxo-1,2,3,7,8,9-hexahydro-6h-purin-6-one	0.714
31	6GO	6-O-methylguanine	0.714
32	8TX	8-thioxo-3,7,8,9-tetrahydro-1h-purine-2,6-dione	0.714
33	FDB	2-amino-5-methyl-3h-pyrrolo[2,3-D]pyrimidin-4(7h)-one	0.714
34	MOG	5-amino-2-methyl-6h-oxazolo[5,4-D]pyrimidin-7-one	0.714
35	PE0	Pterine	0.714
36	T0A	5-deazatetrahydropterin	0.714
37	W5M	9-methyl-9h-purine-2,6-diamine	0.714