1	8HX	8-hydroxy-3,9-dihydro-1h-purine-2,6-dione	1.000
2	URC	Uric acid	1.000
3	MUA	9-methyl uric acid	0.923
4	XAN	Xanthine	0.917
5	IUP	5-(hydro)peroxoisourate	0.857
6	5JQ	2-thioxo-2,3,7,9-tetrahydro-1h-purine-6,8-dione	0.846
7	8TX	8-thioxo-3,7,8,9-tetrahydro-1h-purine-2,6-dione	0.846
8	HPA	Hypoxanthine	0.833
9	EXU	1,3,7-trimethyl-9h-purine-2,6,8-trione	0.800
10	XDS	(5s)-5-(dioxidanyl)-9-methyl-7h-purine-2,6,8-trione	0.800
11	37T	Theobromine	0.786
12	TEP	Theophylline	0.786
13	290	6-methyl-3,9-dihydro-2h-purin-2-one	0.769
14	2ON	2-sulfanyl-1,9-dihydro-6h-purin-6-one	0.769
15	AZA	8-azaxanthine	0.769
16	BOA	2-bromo-6-hydroxy-purine	0.769
17	GUN	Guanine	0.769
18	IGA	6-amino-3,7-dihydro-2h-purin-2-one	0.769
19	209	8-amino-1,3-dimethyl-3,7-dihydropurine-2,6-dione	0.733
20	8NX	8-nitro-3,7-dihydro-1h-purine-2,6-dione	0.733
21	CFF	Caffeine	0.733
22	H33	8-chloro-1,3-dimethyl-3,7-dihydro-1h-purine-2,6-dione	0.733
23	5JL	2,8-dithioxo-1,2,3,7,8,9-hexahydro-6h-purin-6-one	0.714
24	8IG	8-iodo-guanine	0.714
25	9MG	9-methylguanine	0.714
26	ANG	8-aminoguanine	0.714
27	AZ8	Pyrimido[5,4-E][1,2,4]triazine-5,7(6h,8h)-dione	0.714
28	B55	2-amino-8-sulfanyl-1,9-dihydro-6h-purin-6-one	0.714
29	BRG	8-bromoguanine	0.714
30	LUZ	Pteridine-2,4(1h,3h)-dione	0.714
31	MY6	2-amino-7-methyl-1,7-dihydro-6h-purin-6-one	0.714
32	QBK	5-azanyl-[1,3]thiazolo[5,4-D]pyrimidine-2,7-dione	0.714