On the Synthesis and Anticancer Testing of alpha,beta-Unsaturated Ketones as Analogs of Combretastatin-A4
Twenty- one alpha,beta-unsaturated ketone analogs of combretastatin-A4 (CA-4) that were designed for good solubility in aqueous media were synthesized. Compounds defined as Type A were derived from phenylacetone, in which subclass I contained ortho-, meta- or no substituents, sub-class II contained para-substituents, and sub-class III consisted of two substituents. Type B compounds were derived from cyclopropyl 2-fluorobenzyl ketone. The cis-configuration of the target compounds was ascertained through a single crystal X-ray crystallographic analysis of the fluorine-containing compound 8f. Five of the analogs, 8c, 8j and 8l of Type A and 9d and 9i of Type B, were shown to display modest cytotoxic potency (IC50 in the 3.8 - 21 mu M range) against the growth of murine melanoma (B16) and leukemia (L1210) cells in culture. Compounds 8j, 8l and 9i were further tested against MDA-MB-435 human melanoma cells. The cyclopropane-containing compound 9i was the most potent; with an IC50 value of 2.4 mu M. Even though no appreciable effects on interphase microtubules were observed when A-10 cells were treated with 30 mu M 8j or 8l, compound 9i caused extensive microtubule depolymerization at this concentration. These results suggest that compound 9i of Type B has a similar mechanism of action as CA-4 whilst compounds 8j and 8l of Type B are likely to have a different mechanism of action.
Published in: Letters in Drug Design and Discovery, Volume 6, Issue 7, October 1, 2009, pages 531-537. Copyright © 2009 Bentham Science Publishers, Sharjah, U Arab Emirates. The final published version is available at: http://www.benthamscience.com/contents-JCode-LDDD-Vol-00000006-Iss-00000007.htm