Background: A number of unsaturated fatty acids and a few saturated branched-chain fatty acids have been reported to exhibit anticancer activity.

Materials and Methods: In previously reported research, several novel branched-chain derivatives (methyl, n-butyl, phenyl) of methyl oleate were produced by bromination in the allylic position and subsequent treatment with organocuprate reagents. These compounds and their free acid counterparts were tested in vitro for their antiproliferative activities against two cancer cell lines: MCF-7 (human breast) and HT-29 (human colon). In addition, two sets of isomeric tertiary alcohols obtained as side-products in the synthesis of the branched-chain derivatives were evaluated. Testing was performed at three concentration levels (50, 100, and 200 ppm) in dimethyl sulfoxide (DMSO).

Results: The greatest growth inhibitory activity was exhibited by the branched phenyl derivative of oleic acid, with IC50 at 48 ppm against both MCF-7 and HT-29. The branched n-butyl derivative of oleic acid also exhibited significant antiproliferative activity, with IC50 at 82 ppm against MCF-7 and 77 ppm against HT-29.

Conclusion: The observed potent anticancer activity of the n-butyl and phenyl derivatives indicates that certain synthetic branched-chain unsaturated fatty acids have potential in the treatment of cancer and further research is warranted.