Mechanism of toxicity of esters of caffeic and dihydrocaffeic acids.

Ten esters each of caffeic acid and dihydrocaffeic acid have recently been synthesized. Cytotoxicity evaluations of these esters versus L1210 leukemia and MCF-7 breast cancer cells in culture have led to the delineation of substantially different QSAR for each series. The L1210 QSAR for dihydrocaffeic acid esters resembles the QSAR obtained for simple phenols and estrogenic phenols. However, the QSAR pertaining to the caffeic acid esters differs considerably from its sister QSAR. This difference may be attributed to the presence of the olefinic linkage in the side chain. The octyl ester of caffeic acid is nearly ten times as toxic to the leukemia cells than the widely studied phenethyl ester, CAPE.