Selective synthesis and biological evaluation of sulfate-conjugated resveratrol metabolites.

Five resveratrol sulfate metabolites were synthesized and assessed for activities known to be mediated by resveratrol: inhibition of tumor necrosis factor (TNF)alpha induced NF kappa B activity, cylcooxygenases (COX-1 and COX-2), aromatase, nitric oxide production in endotoxin-stimulated macrophages, proliferation of KB or MCF7 cells, induction of quinone reductase I (QRI), accumulation in the sub-G, phase of the cell cycle, and quenching of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical. Two metabolites showed activity in these assays; the 3-sulfate exhibited QRI induction, DPPH free radical scavenging, and COX-1 and COX-2 inhibitory activities and the 4'-sulfate inhibited NF kappa B induction, as well as COX-1 and COX-2 activities. Resveratrol and its 3'-sulfate and 4-sulfate inhibit NO production by NO scavenging and down-regulation of iNOS expression in RAW 264.7 cells. Resveratrol sulfates displayed low antiproliferative activity and negligible uptake in MCF7 cells.