1	GSY	7-(2-hydroxyethyl)-8-mercaptoguanine	1.000
2	B55	2-amino-8-sulfanyl-1,9-dihydro-6h-purin-6-one	0.800
3	MY6	2-amino-7-methyl-1,7-dihydro-6h-purin-6-one	0.800
4	NDM	7,9-dimethylguanine	0.750
5	GUN	Guanine	0.733