1 NDM 7,9-dimethylguanine 1.000 2 9MG 9-methylguanine 0.923 3 MY6 2-amino-7-methyl-1,7-dihydro-6h-purin-6-one 0.923 4 GUN Guanine 0.846 5 8IG 8-iodo-guanine 0.786 6 ANG 8-aminoguanine 0.786 7 B55 2-amino-8-sulfanyl-1,9-dihydro-6h-purin-6-one 0.786 8 BRG 8-bromoguanine 0.786 9 OXG 8-oxoguanine 0.786 10 W5M 9-methyl-9h-purine-2,6-diamine 0.786 11 2BP 9h-purin-2-amine 0.769 12 HPA Hypoxanthine 0.769 13 GSY 7-(2-hydroxyethyl)-8-mercaptoguanine 0.750 14 37T Theobromine 0.733 15 B60 2-amino-8-methyl-7,8-dihydropteridin-4(3h)-one 0.733 16 MUA 9-methyl uric acid 0.733 17 UAN 9-methyl-2-(methylamino)-1h-purin-6-one 0.733 18 2ON 2-sulfanyl-1,9-dihydro-6h-purin-6-one 0.714 19 6AP 9h-purine-2,6-diamine 0.714 20 6GU 6-chloroguanine 0.714 21 7DG 7-deazaguanine 0.714 22 8G8 2-chloranyl-9-methyl-purine 0.714 23 9DG 9-deazaguanine 0.714 24 ADZ 9-methyl-9h-purin-6-amine 0.714 25 AZG 5-amino-1h-[1,2,3]triazolo[4,5-D]pyrimidin-7-ol 0.714 26 BOA 2-bromo-6-hydroxy-purine 0.714 27 DX4 2-amino-1,9-dihydro-6h-purine-6-thione 0.714 28 HH5 6-iodanyl-7~{H}-purin-2-amine 0.714 29 QY8 2-amino-3h,4h,7h-pyrrolo[2,3-D]pyrimidin-4-one 0.714 30 XAN Xanthine 0.714 31 AC2 9-hyroxyethoxymethylguanine 0.706