Development of a novel antioxidant based on a dimeric dihydroisocoumarin derivative

[Display omitted] •Synthesis of a biaryl dimer based on a natural product has been accomplished.•The biaryl dimer displayed more potent antioxidant activity than the monomer.•The biaryl dimer does not display cytotoxicity against cancer cells. A biaryl dimer based on eurotiumide A, a dihydroisocoumarin-type natural product possessing a 1,4-hydroquinone skeleton, was synthesized herein. The radical scavenging activity and cytotoxicity were evaluated. The prepared biaryl dimer and eurotiumide A displayed comparable potent antioxidant activities to those of α-tocopherol and edaravone. However, the biaryl dimer did not show any cytotoxicity against murine colon and human myeloma cells.