. Author manuscript; available in PMC: 2009 Nov 15.

Published in final edited form as: Bioorg Med Chem Lett. 2008 Jul 20;18(22):5867–5870. doi: 10.1016/j.bmcl.2008.07.068

Table 1.

Cytotoxicity (EC₅₀), permeability, and solubility of colchicine, colchicine-504, and colchicine-646.

	HeLa EC₅₀ (µM)^a	HepG2 EC₅₀ (µM)^a	Raji EC₅₀ (µM)^a	Vero EC₅₀ (µM)^a	Perme- ability^b (10⁻ ⁶cm/s)	Solu- bility^c (µM)
Col- chicine	0.039 ±0.006	0.031 ±0.01	0.014 ±0.002	0.53 ±0.09	415 ±47	>250
504	0.36 ±0.07	0.18 ±0.09	0.138 ±0.02	2.3 (±0.9)	108 ±24	32 ±15)
646	1.9 ±0.7	1.2 ±0.6	0.65 ±0.19	>10	<10	<10 ±2

Viability was assessed in a 96 well format. Cells were plated at 2000 cells/well, and drugs were added after 12h. After 48 h, CellTiter-Glow solution was added, and cell viability was measured after 10 min. The EC₅₀ values were obtained by fitting data to the following equation (y = min + (max − min)/1 + (x/Kd) Hill slope). Values reported are the means of two independent experiments done in triplicate.

Permeability (PAMPA) was measured as previously reported.²³

Solubility (PBS + 5% DMSO) was assessed using Multiscreen Solubility assay (Millipore, 96 well plate). Briefly, each compound was serial diluted in PBS:acetonitrile (1:1) and absorbance was measured at 350 nm (calibration). Next, 5 µL of a 10 mM solution of colchicine, colchicine-504 or colchicine-646 was added to 95 µL PBS in a filter plate and agitated for 2h at room temperature. After filtration, absorbance at 350 nm was measured, and concentration was determined on the basis of calibration. Two independent experiments were done in duplicate.