Table 3.

Optimized Aryl Substituents.

				ALDH EC50 (nM) or % Control at 20 µM			CLogP	PEO1 Cell ALDEFLUOR (% inhibition)
No.	R2	R4	R5	1A1	1A2	1A3
2	−H	−H	−H	3700 ± 380	2700 ± 320	700 ± 45	3.94	ND
8	−H			780 ± 78	2200 ± 200	1800 ± 500	5.28	ND
9	−H	−F	−H	2600 ± 400	63%	840 ± 75	4.08	ND
10	−H	−OCH3	−H	36%	47%	41%	3.78	ND
11	−H	−CH3	−H	44%	74%	38%	4.75	ND
12	−H	−Cl	−H	93%	69%	30%	4.80	ND
6	−Cl	−H	−H	190 ± 15	240 ± 57	79 ± 30	4.27	50 ± 4% (10 µM)
13	−Cl	−F	−H	52%	42%	140 ± 21	4.36	59 ± 9% (10 µM)
14	−Cl	−Cl	−H	300 ± 40	3200 ± 1200	520 ± 40	4.73	ND