Table 1.

Mono-substituted coumarin structures and their CAR activation.

Compound	R1	R2	R3	R4	CAR Activation Fold a	Ref
1 5-hydroxycoumarin	OH	H	H	H	6% ± 22%	[25]
2 5-methoxycoumarin	O-methyl	H	H	H	−20% ± 6%	[26,27]
3	O-acetyl	H	H	H	−32% ± 12%	[28]
4	O-allyl	H	H	H	−15% ± 6%	[29]
5	O-n-butyl	H	H	H	−9% ± 14%	[29]
6	O-prenyl	H	H	H	−5% ± 9%	[30]
7	O-geranyl	H	H	H	−18% ± 11%	[30]
8	O-farnasyl	H	H	H	2% ± 14%	[30]
9 6-hydroxycoumarin	H	OH	H	H	−8% ± 11 %	[31]
10 6-methoxycoumarin	H	O-methyl	H	H	32% ± 5%	[32]
11	H	O-trifluoromethyl	H	H	−34% ± 1%	New
12	H	O-acetyl	H	H	−22% ± 3%	[33]
13	H	O-allyl	H	H	−17% ± 6%	[34]
14	H	O-n-butyl	H	H	37% ± 6%	[35]
15	H	O-prenyl	H	H	22% ± 2%	[30]
16	H	O-geranyl	H	H	18% ± 7%	[30]
17	H	O-farnasyl	H	H	−41% ± 9%	[30]
18 umbelliferone	H	H	OH	H	−1% ± 18%	[31,36]
19 7-methoxycoumarin	H	H	O-methyl	H	−9% ± 6%	[25,27,36]
20	H	H	O-trifluoromethyl	H	18% ± 2%	New
21	H	H	O-acetyl	H	−37% ± 12%	[37]
22	H	H	O-allyl	H	−46% ± 11%	[37]
23	H	H	O-n-butyl	H	−51% ± 7%	[38]
24	H	H	O-prenyl	H	−35% ± 13%	[30,39]
25 aurapten	H	H	O-geranyl	H	−13% ± 4%	[30]
26	H	H	O-farnasyl	H	−29% ± 10%	[30]
27 8-hydroxycoumarin	H	H	H	OH	40% ± 38%	[40]
28 8-methoxycoumarin	H	H	H	O-methyl	−8% ± 10%	[41]
29	H	H	H	O-acetyl	−33% ± 13%	[28]
30	H	H	H	O-allyl	−34% ± 12%	[42]
31	H	H	H	O-n-butyl	4% ± 9%	[43]
32	H	H	H	O-prenyl	2% ± 23%	[30]
33	H	H	H	O-geranyl	−30% ± 4%	[30]
34	H	H	H	O-farnasyl	19% ± 25%	[30]

^a CAR activation fold was calculated: (the luminescence value of the tested compound- the luminescence value of scoparone)/the luminescence value of scoparone (as positive control) × 100%.