Table 2. Inhibitory Potency against FAAH, MAGL, and BuChE and Stability in Aqueous PBS Buffer (pH 7.4) of Aryl N-[ω-(6-Fluoroindol-1-yl)pentyl]carbamates and Aryl 4-[2-(6-Fluoroindol-1-yl)ethyl]piperidine-1-carboxylates.

		inhibition IC50 (μM)a			stability (%)b
comp.	R	FAAH	MAGL	BuChE	in PBS buffer	log Pc
14	4-phenyl	0.029	n.a.	4.3	>95	4.1
26	4-fluorophenyl	0.049	n.a.	7.1	>95	4.2
27	3-fluorophenyl	0.015	>10d	1.5	>95	4.3
28	2-fluorophenyl	0.017	3.7	0.74	91 ± 3	4.1
29	4-cyanophenyl	n.t.	n.t.	n.t.	12 ± 3	3.8
30	3-cyanophenyl	0.008	0.38	0.38	72 ± 3	3.8
31	2-cyanophenyl	n.t.	n.t.	n.t.	3 ± 2	3.9
33	4-carboxyphenyl	0.012	3.3	0.97	>95	2.8
35	3-carboxyphenyl	0.018	>10e	5.8	>95	2.8
37	2-carboxyphenyl	0.038	0.038	2.3	73 ± 6	2.7
39	4-(carboxymethyl)phenyl	0.014	n.a.	>10f	>95	2.7
41	3-(carboxymethyl)phenyl	0.058	n.a.	>10g	>95	2.8
43	2-(carboxymethyl)phenyl	4.2	n.a.	>10h	>95	2.8
44	pyridin-3-yl	0.002	0.17	0.27	60 ± 2	2.6
45	2-methylpyridin-3-yl	0.010	0.14	0.40	75 ± 4	2.7
46	4-methylpyridin-3-yl	0.003	0.15	0.36	74 ± 4	2.7
47	5-methylpyridin-3-yl	0.002	0.15	0.24	72 ± 4	2.9
48	6-methylpyridin-3-yl	0.004	0.31	0.36	82 ± 6	2.8
49	indol-4-yl	0.18	n.a.	0.55	>95	3.5
54	4-carboxy	0.015	n.a.	n.a.	>95	3.6
56	3-carboxy	0.027	n.a.	n.a.	>95	3.6
58	2-carboxy	3.5	n.a.	n.a.	>95	3.4
URB597 (1)		0.043	n.a.	>10i	>95	2.0
ABX-1431 (2)		n.a.	0.58	n.a.	90 ± 5	7.4
physostigmine		n.a.	n.a.	2.7	>95	0.6

^aValues are the means of at least two independent determinations; errors are within ± 20; n.t., not tested; n.a., not active at 10 μM.

^bPercent of parent remaining after incubation in PBS buffer (pH 7.4) for 60 min; values are means ± standard deviations of independent determinations (n = 3).

^cExperimentally determined by reversed-phase HPLC.

^d39% at 10 μM.

^e31% at 10 μM.

^f38% at 10 μM.

^g42% at 10 μM.

^h34% at 10 μM.

ⁱ35% at 10 μM.