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