Table 1.

IC₅₀ values of hexyl-substituted 1-(5-oxovalerate)indoles. A series of 1-(5-oxovalerate)indoles containing a hexyl substituent at various positions as well as 2-hexyl-1-(5-oxovalerate)indoles containing a chloro substituent at positions 5 or 6 were tested in the calcium mobilization assay as shown in Figure 5. IC₅₀ values were determined from concentration- response curves for each individual experiment.

Indole	IC50 (µM)
2-Hx (26)	1.55 ± 0.25 (11)
3-Hx (16)	20.68 ± 5.60 (4) ***
5-Hx (17)	17.67 ± 3.59 (3) **
6-Hx (18)	18.00 ± 2.65 (3) **
7-Hx (19)	11.77 ± 2.51 (3) *
5-Cl (33)	1.17 ± 0.32 (4)
6-Cl (39)	0.40 ± 0.03 (7) **

The values are means ± SE with the numbers of independent determinations shown in brackets. Statistically significant differences compared to 26 are shown as follows:

^*p<0.05;

^**p<0.005;

^***p<0.001

(one-way ANOVA with a Holm-Sidak post-hoc test).