Dimer and Tetramer of Gallic Acid: Facile Synthesis, Antioxidant and Antiproliferative Activities

In view of the various and promising biological activities of gallic acid, we designed and prepared a series of poly-phenolic compounds carrying multi-gallic acids residues. These dimer and tetramer of gallic acids were facilely synthesized by convergent approach. Subsequently, antioxidant activity evaluation was carried out using DPPH assay, and the resulting polyphenol exerted enhanced activity to gallic acid monomer. Antiproliferative activity evaluation was performed using MTT assay with three human cancer cell lines (Hela, A549 and MCF-7) and two human normal cell lines (HEK293 and HUVEC). The cytotoxicity of the dimer and tetramer of gallic acid were higher than that of the monomer against both cancer and normal cell lines, however the cytotoxicity of the dimer and tetramer against cancer cells was much fiercer than normal cells, which resulted in better selectivity. Consequently, vanlency effects embodied in both antioxidant and antiproliferative activities of the obtained multi-gallic acid derivatives.