1 HGL (2s)-2-amino-4-(2-amino-6-oxo-1,6-dihydro-9h-purin-9-yl)butanoic acid 1.000 2 PE2 9-(4-hydroxy-3-(hydroxymethyl)but-1-yl)guanine 0.800 3 ZD2 (2s)-4-(6-amino-9h-purin-9-yl)-2-hydroxybutanoic acid 0.750 4 DEA D-eritadenine 0.714 5 JYW 4-(6-azanyl-8-bromanyl-purin-9-yl)butan-1-ol 0.700