1	HPA	Hypoxanthine	1.000
2	2ON	2-sulfanyl-1,9-dihydro-6h-purin-6-one	0.909
3	BOA	2-bromo-6-hydroxy-purine	0.909
4	GUN	Guanine	0.909
5	XAN	Xanthine	0.909
6	WUT	9~{H}-purine	0.900
7	5JL	2,8-dithioxo-1,2,3,7,8,9-hexahydro-6h-purin-6-one	0.833
8	5JQ	2-thioxo-2,3,7,9-tetrahydro-1h-purine-6,8-dione	0.833
9	8HX	8-hydroxy-3,9-dihydro-1h-purine-2,6-dione	0.833
10	8IG	8-iodo-guanine	0.833
11	8TX	8-thioxo-3,7,8,9-tetrahydro-1h-purine-2,6-dione	0.833
12	9MG	9-methylguanine	0.833
13	A1LXN	2-azanyl-8-methyl-1,9-dihydropurin-6-one	0.833
14	ANG	8-aminoguanine	0.833
15	B55	2-amino-8-sulfanyl-1,9-dihydro-6h-purin-6-one	0.833
16	BRG	8-bromoguanine	0.833
17	I7U	3-methyl-7~{H}-purine-2,6-dione	0.833
18	MY6	2-amino-7-methyl-1,7-dihydro-6h-purin-6-one	0.833
19	OXG	8-oxoguanine	0.833
20	URC	Uric acid	0.833
21	2BP	9h-purin-2-amine	0.818
22	6MP	6-methylpurine	0.818
23	7HX	7h-pyrrolo[2,3-D]pyrimidin-4-ol	0.818
24	9HX	9-deazahypoxanthine	0.818
25	BP1	6-bromo-7h-purine	0.818
26	ES4	6-chloro-9h-purine	0.818
27	28Y	3h-imidazo[2,1-B]purin-4(5h)-one	0.769
28	37T	Theobromine	0.769
29	MUA	9-methyl uric acid	0.769
30	NDM	7,9-dimethylguanine	0.769
31	TEP	Theophylline	0.769
32	UAN	9-methyl-2-(methylamino)-1h-purin-6-one	0.769
33	06K	2,6-bis(chloranyl)-7h-purine	0.750
34	290	6-methyl-3,9-dihydro-2h-purin-2-one	0.750
35	3MA	6-amino-3-methylpurine	0.750
36	6AP	9h-purine-2,6-diamine	0.750
37	6GU	6-chloroguanine	0.750
38	7DG	7-deazaguanine	0.750
39	8G8	2-chloranyl-9-methyl-purine	0.750
40	9DG	9-deazaguanine	0.750
41	9QC	5-azanyl-3,6-dihydro-[1,2,3]triazolo[4,5-D]pyrimidin-7-one	0.750
42	A2F	2-fluoroadenine	0.750
43	ADK	3-methyl-3h-purin-6-ylamine	0.750
44	ADZ	9-methyl-9h-purin-6-amine	0.750
45	AZA	8-azaxanthine	0.750
46	AZG	5-amino-1h-[1,2,3]triazolo[4,5-D]pyrimidin-7-ol	0.750
47	BCP	2-bromo-6-chloro-purine	0.750
48	CFP	6-chloro-2-fluoropurine	0.750
49	DX4	2-amino-1,9-dihydro-6h-purine-6-thione	0.750
50	HH5	6-iodanyl-7~{H}-purin-2-amine	0.750
51	IGA	6-amino-3,7-dihydro-2h-purin-2-one	0.750
52	KB5	6-azanyl-9~{H}-purine-8-thiol	0.750
53	KBQ	2-sulfanylidene-1,7-dihydropyrrolo[2,3-D]pyrimidin-4-one	0.750
54	M1A	6-amino-1-methylpurine	0.750
55	N6M	N-methyl-9h-purin-6-amine	0.750
56	Q88	9h-purine-6,8-diamine	0.750
57	QY8	2-amino-3h,4h,7h-pyrrolo[2,3-D]pyrimidin-4-one	0.750
58	SZL	6-methoxy-9h-purine	0.750
59	XQG	6-methylsulfanyl-9h-purine	0.750
60	YH7	6-amino-1,9-dihydro-2h-purine-2-thione	0.750
61	WOY	6,7-dihydro-5h-pyrrolo[2,3-D]pyrimidine	0.727
62	209	8-amino-1,3-dimethyl-3,7-dihydropurine-2,6-dione	0.714
63	8NX	8-nitro-3,7-dihydro-1h-purine-2,6-dione	0.714
64	A1BD3	Enprofylline	0.714
65	CFF	Caffeine	0.714
66	H33	8-chloro-1,3-dimethyl-3,7-dihydro-1h-purine-2,6-dione	0.714
67	IUP	5-(hydro)peroxoisourate	0.714
68	Q44	N-(6-oxo-6,9-dihydro-3h-purin-2-yl)acetamide	0.714