TABLE 2.

Screening of 4, 5, and 6 position-substituted benzothiazoles on KCa2.3 and KCa3.1

The reported numbers are the ratios of slope conductance at −80 mV measured in the presence and absence of drug with 250 nM [Ca²⁺]_i.

Compound			KCa2.3			KCa3.1
			1 μM	10 μM	100 μM	1 μM	10 μM	100 μM
1	Riluzole		1.1 ± 0.3	11.5 ± 4	30 ± 3	6 ± 0.9	30 ± 1.5	30 ± 2
8	SKA-1		N.E.	1.9 ± 0.3	N.D.	1.3 ± 0.2	3.1 ± 0.3	35 ± 4
9	SKA-36		N.E.	1.2 ± 0.2	15.5 ± 2	N.E.	1.2 ± 0.2	17 ± 1
10	SKA-4		N.E.	1.2 ± 0.3	N.D.	N.E.	1.2 ± 0.1	1.3 ± 0.1
11	SKA-16		N.E.	N.E.	N.E.	N.E.	1.5 ± 0.3	1.1 ± 0.3
12	SKA-24		N.E.	N.E.	N.E.	N.E.	4.0 ± 0.5	13 ± 2
13	SKA-2		N.E.	2.0 ± 0.3	N.D.	N.E.	1.1 ± 0.1	5.1 ± 0.4
14	SKA-17		N.E.	1.4 ± 0.2	2.1 ± 1.0	1.4 ± 0.3	1.3 ± 0.4	2.2 ± 0.3
15	SKA-13		1.8 ± 0.2	3.3 ± 0.5	36 ± 4	1.3 ± 0.3	5.0 ± 1.0	29 ± 5
16	SKA-7		N.E.	N.E.	N.E.	N.E.	1.5 ± 0.3	14 ± 2
17	SKA-32		N.E.	N.E.	N.E.	N.E.	N.E.	N.E.
18	SKA-22		N.E.	1.4 ± 0.2	Insoluble	N.E.	1.2 ± 0.3	Insoluble
19	SKA-48		1.9 ± 0.1	12 ± 4	39 ± 8	4.3 ± 0.8	40 ± 7	35 ± 8
20	SKA-18		1.8 ± 0.2	6.5 ± 0.5	42 ± 5	3.0 ± 0.5	32 ± 5	39 ± 5
21	SKA-42		1.5 ± 0.1	3.5 ± 1.5	35 ± 5	1.3 ± 0.5	2.8 ± 6	14 ± 2
22	SKA-3		2.2 ± 0.4	14 ± 3	32 ± 3	2.0 ± 0.5	38 ± 3	41 ± 3
23	SKA-8		1.1 ± 0.2	7.4 ± 0.5	32 ± 3	6.0 ± 0.7	38 ± 5	34 ± 6
24	SKA-35		1.6 ± 0.5	3.5 ± 1.0	24 ± 3	1.2 ± 0.5	5 ± 3	26 ± 4
25	SKA-51		2.2 ± 0.9	18 ± 3	N.D.	1.6 ± 0.5	35 ± 7	N.D.
26	SKA-34		1.4 ± 0.3	2.5 ± 0.5	33 ± 5	2.5 ± 0.5	13 ± 6	32 ± 2
27	SKA-19		1.5 ± 0.3	10 ± 1	30 ± 3	1.2 ± 0.2	12 ± 4	29 ± 4
28	SKA-11		2.3 ± 0.9	22 ± 4	30 ± 5	3.0 ± 2	10 ± 3	19 ± 5
29	SKA-53		N.E.	Insoluble	Insoluble	N.E.	Insoluble	Insoluble

N.E., no effect; N.D., not determined.