1	CFF	Caffeine	1.000
2	EXU	1,3,7-trimethyl-9h-purine-2,6,8-trione	0.933
3	37T	Theobromine	0.929
4	TEP	Theophylline	0.929
5	A1IOQ	7-(2-chloroethyl)-1,3-dimethyl-purine-2,6-dione	0.875
6	E7R	1,3-dimethyl-7-propyl-purine-2,6-dione	0.875
7	209	8-amino-1,3-dimethyl-3,7-dihydropurine-2,6-dione	0.867
8	H33	8-chloro-1,3-dimethyl-3,7-dihydro-1h-purine-2,6-dione	0.867
9	I7U	3-methyl-7~{H}-purine-2,6-dione	0.857
10	7UM	3-methyl-7-propyl-purine-2,6-dione	0.812
11	XAN	Xanthine	0.786
12	A1BD2	Dyphylline	0.778
13	X0T	7-[(2s)-2,3-dihydroxypropyl]-1,3-dimethyl-3,7-dihydro-1h-purine-2,6-dione	0.778
14	IBM	3-isobutyl-1-methylxanthine	0.765
15	A1BD3	Enprofylline	0.750
16	7UH	Doxofylline	0.737
17	M1D	4-(1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydro-7h-purin-7-yl)butanoic acid	0.737
18	QOK	7-(2-methoxyethoxymethyl)-1,3-dimethyl-purine-2,6-dione	0.737
19	8HX	8-hydroxy-3,9-dihydro-1h-purine-2,6-dione	0.733
20	8TX	8-thioxo-3,7,8,9-tetrahydro-1h-purine-2,6-dione	0.733
21	MY6	2-amino-7-methyl-1,7-dihydro-6h-purin-6-one	0.733
22	URC	Uric acid	0.733
23	HPA	Hypoxanthine	0.714
24	PNX	3,7-dimethyl-1-(5-oxohexyl)-3,7-dihydro-1h-purine-2,6-dione	0.700