Table 3. Efficiency and Potency of Further Characterized Piperine Derivatives and Piperine^a.

compd	IGABA-max (%)	EC50 (μM)	nH	n
piperine	302 ± 27	52.4 ± 9.3	1.5 ± 0.2	3
22	1581 ± 74**	86.7 ± 13.9	2.3 ± 0.2	6
23	1673 ± 146**	51.7 ± 9.5	3.1 ± 0.8	6
25	760 ± 47**	13.8 ± 1.8**	1.8 ± 0.1	6
35	733 ± 60**	67.7 ± 11.0	1.9 ± 0.3	6
43	505 ± 24**	23.1 ± 3.3*	1.6 ± 0.2	6
47	603 ± 87*	70.8 ± 21.1	1.2 ± 0.2	3
53	388 ± 64	55.3 ± 17.6	1.5 ± 0.2	3
56	165 ± 4**	36.8 ± 2.0	1.2 ± 0.0	3
72	706 ± 58**	102.0 ± 11.2	1.9 ± 0.2	5
73	480 ± 85	31.8 ± 5.3	2.7 ± 0.2	6

^aFrom ref (31), including number of experiments n. Asterisks indicate significant differences from piperine: *p < 0.05; **p < 0.01.