Synthesis of a novel ester of hydroxytyrosol and lipoic acid exhibiting an antiproliferative effect on human colon cancer HT-29 cells

A novel hydroxytyrosol-lipoic acid derivative has been synthesized. Key steps are an esterification reaction between tyrosol and cJipoic acid derivatives and a regioselective aromatic hydroxylation ofthe monohydroxylated ester performed by 2-iodoxybenzoic acid (IBX) followed by an in situ reductionw ith sodium dithionite (Na2S2O4T).h e novel estere xhibited an antiproliferative effect on the human colorectal adenocarcinoma HT-29 cell line signifrcantly more potent than its parent compounds