Inhibitory potency of 3-hydroxy-2-arylbenzo[h]quinolin-4(1H)-ones 3a–d, 2-arylbenzo[h]quinolin-4(1H)-one 3eand its chemical isomers 4a,b against CYP1B1, CYP1A1, and CYP1A2.

Compound	R1	R	IC50 values (nM)			IC50 ratio
			1B1	1A1	1A2	1A1/1B1	1A2/1B1
3a	OH	H	86.7	897.7	>5000	10.4	>57.7
3b	OH	o-F	85.9	1783	>5000	20.8	>58.2
3c	OH	p-OH	141.7	525.1	>5000	3.7	>35.3
3d	OH	p-F	93.3	333.5	>5000	3.6	>53.6
3e	H	H	17.3	103.2	483.5	6.0	27.9
4a	OH	—	7.6	18.5	146.9	2.4	19.3
4b	OCH3	—	NIa	NI	NI	—	—

^aNI = no inhibition.