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) α induced NFκB 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 1 (QR1), accumulation in the sub-G1 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 QR1 induction, DPPH free radical scavenging, and COX-1 and COX-2 inhibitory activities and the 4′-sulfate inhibited NFκB 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.