1	SPT	5'-thio-thymidine phosphonic acid	1.000
2	TPC	5'-thio-2'-deoxy-cytosine phosphonic acid	0.864
3	WUV	5'-thiothymidine	0.810
4	0DN	5'-deoxy-5'-fluorothymidine	0.727
5	5AT	5'-amino-5'-deoxythymidine	0.727
6	LLT	L-deoxythymidine	0.727
7	THM	Thymidine	0.727
8	DDU	2'-5'dideoxyuridine	0.714