The reactions of resveratrol with proinflammatory oxidants including hypochlorous and hypobromous acids in phosphate-buffered saline/methanol solution were carried out and eight halogenated resveratrol derivatives differing in the number and position of halogen atoms, and the configuration of double bond were obtained. Halogenation of resveratrol took place only at the aromatic A ring, and interestingly, the halogenation increased antioxidant activity of this parent molecule in the 2,2′-azobis(2-amidinopropane) hydrochloride-induced RBC haemolysis model. Additionally, antimicrobial activity of the derivatives against Gram-positive bacteria, Gram-negative bacteria and fungi were tested, and toward Candida albicans, 2-chloro-resveratrol and 2-bromo-resveratrol were more active than the unmodified form and the reference compound fluconazole.Highlights► The fate of resveratrol in the presence of HOCl or HOBr was determined. ► Eight chlorinated and brominated resveratrols were formed in the reactions. ► Halogenation of resveratrol increased its anti-hemolysis activity. ► Halogenation of resveratrol can modify its antimicrobial profile.

Based on the observed biological activities of coumarins and resveratrol, we synthesized fourteen hydroxylated 3-phenylcoumarins (stilbene-coumarin hybrids) including six novel ortho-hydroxy-methoxy substituted derivatives, 1–14, by Perkin reaction. We characterized these compounds concerning their antioxidant activity against 2,2′-azobis(2-amidinopropane hydrochloride) (AAPH)-induced pBR322 DNA strand breakage, and their antiproliferative effects on human promyelocytic leukemia HL-60 and human lung adenocarcinoma epithelial A549 cells. Structure–activity relationship information suggests that the introduction of ortho-hydroxy-methoxy groups and ortho-dihydroxy groups on the aromatic A ring could efficiently improve antiproliferative activity. Interestingly, a new derivative, 6-methoxy-7-hydroxy-3-(4′-hydroxyphenyl)coumarin, 9, behaved as a poor antioxidant but appeared to be the most potent antiproliferative agent among the compounds examined, and this activity was mediated by deregulation in cell cycle and induction of apoptosis.A new stilbene-coumarin hybrid, 6-methoxy-7-hydroxy-3-(4′-hydroxyphenyl)coumarin, 9, behaved as a poor antioxidant but appeared to be the most potent antiproliferative agent among the synthesized 3-phenylcoumarins, and this activity was mediated by deregulation in cell cycle and induction of apoptosis.