1	721	3-butoxy-1-(2,2-diphosphonoethyl)pyridinium	1.000
2	722	1-(2,2-diphosphonoethyl)-3-(heptyloxy)pyridinium	0.875
3	714	1-(2,2-diphosphonoethyl)-3-(octyloxy)pyridinium	0.840
4	B71	3-(decyloxy)-1-(2,2-diphosphonoethyl)pyridinium	0.778