Table 1.

Helicase inhibition and viral replication inhibition data for UK-1 and analogs 1-6.

Compound	Helicasea		Repliconc,d
	DNA	RNA
	IC50(μM)b	IC50(μM)b	EC50 (μM)e	CC50 (μM)f	SI50g
UK-1	380	>1200	0.77	17	22
1	>1800	>1800	0.50	5.4	11
2	>1800	>1800	0.53	3.5	6.6
3	>1800	>1800	1.4h	6.3h	4.5h
4	540	590	0.53	2.5	4.7
5	3.8	20	2.1	>20	>10
6	2.6	20	0.54	>20	>37

^aStrand separation of radiolabeled oligonucleotides was monitored using gel electrophoresis (see Supplemental Information).

^bThe concentration of compound required to inhibit 50% of helicase activity.

^cExperiments were carried out at Southern Research Institute, Frederick, MD.

^dResults are the averages of 2–4 independent dose-response experiments using a combination of luciferase reporter-based and RNA assays unless noted.

^eThe concentration of compound that inhibits 50% of viral RNA replication.

^fThe concentration of compound that kills 50% of the cells.

^gThe ratio of EC₅₀ to CC₅₀.

^hResult is from a single luciferase reporter-based assay.