1	37T	Theobromine	1.000
2	CFF	Caffeine	0.929
3	I7U	3-methyl-7~{H}-purine-2,6-dione	0.923
4	7UM	3-methyl-7-propyl-purine-2,6-dione	0.867
5	EXU	1,3,7-trimethyl-9h-purine-2,6,8-trione	0.867
6	TEP	Theophylline	0.857
7	XAN	Xanthine	0.846
8	A1IOQ	7-(2-chloroethyl)-1,3-dimethyl-purine-2,6-dione	0.812
9	E7R	1,3-dimethyl-7-propyl-purine-2,6-dione	0.812
10	209	8-amino-1,3-dimethyl-3,7-dihydropurine-2,6-dione	0.800
11	A1BD3	Enprofylline	0.800
12	H33	8-chloro-1,3-dimethyl-3,7-dihydro-1h-purine-2,6-dione	0.800
13	8HX	8-hydroxy-3,9-dihydro-1h-purine-2,6-dione	0.786
14	8TX	8-thioxo-3,7,8,9-tetrahydro-1h-purine-2,6-dione	0.786
15	MY6	2-amino-7-methyl-1,7-dihydro-6h-purin-6-one	0.786
16	URC	Uric acid	0.786
17	HPA	Hypoxanthine	0.769
18	MUA	9-methyl uric acid	0.733
19	NDM	7,9-dimethylguanine	0.733
20	A1BD2	Dyphylline	0.722
21	X0T	7-[(2s)-2,3-dihydroxypropyl]-1,3-dimethyl-3,7-dihydro-1h-purine-2,6-dione	0.722
22	290	6-methyl-3,9-dihydro-2h-purin-2-one	0.714
23	2ON	2-sulfanyl-1,9-dihydro-6h-purin-6-one	0.714
24	3MA	6-amino-3-methylpurine	0.714
25	ADK	3-methyl-3h-purin-6-ylamine	0.714
26	AZA	8-azaxanthine	0.714
27	BOA	2-bromo-6-hydroxy-purine	0.714
28	GUN	Guanine	0.714
29	IGA	6-amino-3,7-dihydro-2h-purin-2-one	0.714
30	IBM	3-isobutyl-1-methylxanthine	0.706