. Author manuscript; available in PMC: 2012 Oct 13.

Published in final edited form as: J Med Chem. 2011 Sep 16;54(19):6919–6935. doi: 10.1021/jm2008985

Table 5.

Cytotoxicity of o-F- and o-Cl-amidine in combination with Doxorubicin in HL-60 cells.

Conditions	EC₅₀^a (μM)	% Survival
Doxorubicin	2.50 ± 1.16	12.0 ± 4.4
Doxorubicin + 100 nM o-Cl-amidine	0.39 ± 0.02	ND^b
Doxorubicin + 1 μM o-Cl-amidine	0.34 ± 0.03	ND^b
Doxorubicin + 10 μM o-Cl-amidine	0.34 ± 0.12	ND^b
Doxorubicin + 100 nM o-F-amidine	0.45 ± 0.12	ND^b
Doxorubicin + 1 μM o-F-amidine	0.44 ± 0.03	ND^b
Doxorubicin + 10 μM o-F-amidine	0.42 ± 0.01	ND^b
Doxorubicin + 1 μM Cl-amidine	1.42 ± 0.02	ND^b
Doxorubicin + 10 μM Cl-amidine	1.29 ± 0.04	ND^b
Doxorubicin + 100 μM Cl-amidine	0.14 ± 0.09	ND^b
Doxorubicin + 1 μM F-amidine	2.33 ± 1.74	8.14 ± 5.10
Doxorubicin + 10 μM F-amidine	1.30 ± 0.66	ND^b
Doxorubicin + 100 μM F-amidine	0.49 ± 0.25	ND^b

EC₅₀ is defined as the concentration of agent that reduces cell viability to 50% of maximum.

EC₅₀ values were determined by fitting the dose response data to equation 1. % survival is based on the cell viability at the maximum agent concentration tested.

ND: no viable cells were detected as defined by the lack of absorbance above the 100% killing control.