Novel analogues of resveratrol: metabolism and inhibition of colon cancer cell proliferation

Resveratrol is a phytochemical present in the skin of red grapes, and hence red wine as well as a variety of berries and nuts. It is an anti-oxidant, which has shown cancer chemopreventive properties in preclinical rodent models of carcinogenesis. The bioavailability of resveratrol is low, as it is rapidly metabolised to glucuronides and sulfates. The pharmacological activities of conjugate metabolites of phenols are often much lower than those of their metabolic progenitors. Therefore chemical synthetic manipulations aimed at slowing the rate of metabolic conjugation of phenols may generate analogues with increased bioavailability and efficacy. Here we describe the synthesis using the Wittig-Horner-Emmons reaction of a new series of resveratrol analogues in which the phenol moieties were systematically replaced by hydroxymethyl and/or methoxy groups. Incubation of analogues, which lack phenol groups with phase II metabolising enzyme preparations generated hardly any, or only small amounts of, conjugates. Four of the new analogue inhibited the growth of human-derived HCA-7 colon cancer cells, but with much less potency than resveratrol.