Table 1.

Summary of biophysical and biochemical properties of 3-indolylmethanamines.

Compound	Solubility (μM)a	Permeabilityb Log (Pe) (cm/s)	VDR-SRC2-3 IC50 (μM)c	VDR-mediated Transcription IC50 (μM)d	Toxicity LC50 (μM)e
1	3.6	7.36 ± 0.10	12.8 ± 0.8	n.o.	36.4 ± 7.4
2	57.9	7.03 ± 0.07	7.2 ± 0.4	3.0 ± 0.7	> 50
3	96.5	6.26 ± 0.02	22.8 ± 2.2	2.2 ± 0.5	15.3 ± 1.7
4	91.5	6.64 ± 0.02	21.8 ± 1.7	4.4 ± 2.1	14.1 ± 1.6
5	94.0	6.16 ± 0.02	11.3 ± 0.5	3.2 ± 0.7	41.7 ± 13.3
6	48.1	5.86 ± 0.03	n.o.	9.3 ± 3.1	> 100
7	25.2	6.26 ± 0.01	17.2 ± 4.8	5.0 ± 3.4	> 75
8	8.5	7.42 ± 0.52	15.6 ± 1.4	5.2 ± 2.7	> 50
9	19.8	7.68 ± 0.31	63.1 ± 13.6	7.3 ± 2.9	> 100
10	29.4	n.d.	n.o.	5.8 ± 3.1	> 75
PS121912	68.9	6.36 ± 0.02	12.4 ± 0.7(8.1 ±2.3)f	0.59 ± 0.1	27.3 ± 2.7
12	60.4	6.21 ± 0.01	7.2 ± 0.4	5.4 ± 3.5	42.7 ± 2.7
13	45.5	5.60 ± 0.19	59.9 ± 4.5	5.8 ± 2.1	> 75
14	18.2	6.67 ± 0.04	35.2 ±12.5	9.1 ± 2.2	53.7 ± 16.8
15	20.1	6.41 ± 0.01	9.5 ± 0.4	3.4 ± 0.6	10.8 ± 1.6
16	123.3	6.47 ± 0.11	> 75	3.2 ± 1.4	> 100
17	128.3	6.50 ± 0.14	51.5 ± 10.4	3.7 ± 1.8	> 100
18	52.8	7.57 ± 0.32	14.2 ± 1.4	14.1 ± 6.6	> 100
19	3.6	n.d.	66.8 ± 10.3	n.o.	> 100
20	176.7	6.71 ± .01	16.7 ± 0.8	6.1 ± 2.5	> 75
21	97.9	6.14 ± 0.13	11.9 ± 0.7	3.8 ± 2.1	> 75
22	99.3	6.92 ± 0.16	n.o.	n.o.	> 100
23	114.4	n.d.	> 75	n.o.	> 75
24	3.0	n.d.	n.o.	> 25	> 100
25	95.3	6.68 ± 0.11	15.8 ± 1.2	> 25	> 75
26	130.1	5.87 ± 0.01	101.4 ± 15.2	12.2 ± 3.3	> 75
27	120.3	6.09 ± 0.01	29.3 ± 5.7	6.7 ± 2.5	> 100
28	101.8	6.14 ± 0.04	17.3 ± 0.7	8.5 ± 2.7	> 50
29	150.2	5.78 ± 0.01	32.3 ± 6.4	5.4 ± 2.1	18.6 ± 2.5
30	144.8	5.88 ± 0.02	n.o.	n.d.	> 75

^aSolubility was determined in phosphate-buffered saline at pH 7.4;

^bPermeability was measured using the parallel artificial membrane permeation assay (PAMPA) at neutral pH (pH = 7.4).;

^cA fluorescence polarization competition assay was carried out using VDR-LBD (1 μM), Alexa Fluor-labeled peptide SRC2-3 (7 nM), VDR-agonist LG190178 (5 μM), and serial diluted small molecules. IC₅₀ values were obtained by fitting data obtained after 2 hours to the following equation: $\mathrm{Y}=\text{Bottom}+(\text{Top}-\text{Bottom})/(1+10^((\text{LogIC}50-\mathrm{X})\ast \text{HillSlope}))$ using three independent experiments in quadruplet; Transcription assay: HEK293T cells were transfected with CMV-VDR and a CYP24A1 promoter driven luciferase expression vector in the presence of 1,25(OH)₂D₃;

^eToxicity was determined under the conditions of the transcription assay using CellTiter-Glo;

^fTwo-hydrid assay: HEK293T cells were transfected with a VP16-VDR-LBD, SRC1-GAL4, and luciferase reporter plasmid vector in the presence of 1,25(OH)₂D₃.²¹

n.d. = not determined; n.o. = not observed.