1	C6J	[2-(1-methylpyridin-2-yl)-1-phosphono-ethyl]phosphonic acid	1.000
2	C6M	[1-phosphono-2-(1-propylpyridin-2-yl)ethyl]phosphonic acid	0.895
3	RIS	1-hydroxy-2-(3-pyridinyl)ethylidene bis-phosphonic acid	0.700