Antioxidative polyphenols from berries of Pimenta dioica

摘要

The ethyl acetate-soluble part of allspice, berries of Pimenta dioica, showed strong antioxidant activity and radical-scavenging activity against l,l-diphenyl-2-picrylhydrazyl (DPPH) radical. From the ethyl acetate-soluble part, two new compounds, 5-galloyloxy-3,4-dihydroxypentanoic acid and 5-(5-carboxymethyl-2-oxocyclopentyl)-3Z-pentenyl 6-O-galloyl-/3-D-glucoside were isolated together with 11 known polyphenols by repeated column chromatography. Their structures were elucidated on the basis of MSand various NMR spectroscopic data.All isolated compounds were evaluated for antioxidative effects on oxidation of methyl linoleate under aeration and heating, and on peroxidation of liposome induced by 2,2-azobis-(2-amidinopropane)dihydrocloride (AAPH)as a water-soluble initiator along with their radical-scavenging activity against DPPH. Quercetin and its glycosides showed remarkable activity for scavenging DPPH radical and inhibiting peroxidation of liposome. Two new compounds also exhibited strong DPPH radical-scavenging activity and inhibitory effect on the peroxidation of liposome as myricetin.