Antioxidant and antitumor activities of 4-arylcoumarins and 4-aryl-3,4-dihydrocoumarins

Five 4-arylcoumarins (1c-g) and twelve 3,4-dihydro-4-arylcoumarins (2a-l) were synthesized and tested for antioxidant activity, antitumor activity, toxicity and structure-activity relationships analysis. 4-Arylcoumarins and 3,4-dihydro-4-arylcoumarins that possess two hydroxyl groups in ortho position, such as 1d, 1f, 2a, 2f, 2g and 2h had stronger radical scavenging properties than that of vitamin C (Vit C) in ABTS(center dot+) assay. Kinetic traces of scavenging ABTS(center dot+) and DPPH radicals showed that all the reaction could reached endpoint in 1 min, which was similar with Vit C. 4-Arylcoumarins with 3'-hydroxyl-4'-methylphenyl structural show more efficient NO center dot radical scavenging activity. Three compounds 2e, 1f and 2a, in particular had superior EC50 for NO center dot scavenging than did Vit C. MTT assay indicated that one compound in particular had a potential antitumor effect, inhibiting proliferation of BGC-823 cells and almost completely killing them at a concentration 62.5 mg/L. With same concentration 100 mu g/mL, hemolytic analysis in rabbit red blood cells showed that only two compounds had hemolytic activity with a little more than 5% hemolysis. Injection and oral toxicity tests on Galleria mellonella larvae showed that none of the tested 4-arylcoumarins significantly affected their appetite, viability and mortality. (C) 2014 Elsevier B.V. and Societe francaise de biochimie et biologie Moleculaire (SFBBM). All rights reserved.