Table 1. Summary of Biophysical and Biochemical Properties of 3-Indolylmethanamines.
| compd | 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 ± 0.01 | 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 |
Solubility was determined in phosphate-buffered saline at pH 7.4.
Permeability was measured using the parallel artificial membrane permeation assay (PAMPA) at neutral pH (pH = 7.4).
A 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 h to the following equation: Y = bottom + (top – bottom)/(1 + 10((log IC50 – X)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.
Toxicity was determined under the conditions of the transcription assay using CellTiter-Glo.
Two-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.