1	CBQ	[(5-chloro-pyridin-2-ylamino)-phosphono-methyl]-phosphonic acid	1.000
2	3YQ	{[(3-methylpyridin-2-yl)amino]methanediyl}bis(phosphonic acid)	0.889
3	IMB	[(isoquinolin-1-ylamino)-phosphono-methyl]-phosphonic acid	0.762
4	BWJ	{[(3,5-dichlorophenyl)amino]methylene}bis(phosphonic acid)	0.750