Activity-guided separation of antioxidant response element (ARE)-inducing constituents from the rhizomes of Atractylodis Rhizoma Alba was performed by the combination of centrifugal partition chromatography (CPC) and an ARE luciferase reporter assay. From 3 g of the active n-hexane fraction, one polyacetylene, (6E,12E)-tetradeca-6,12-dien-8,10-diyne-1,3-diyl diacetate (47.3 mg), and two sesquiterpenes, atractylenolide I (40.9 mg), and selina-4(14),7(11)-dien-8-one (6.0 mg) were successfully isolated by CPC with n-hexane–ethyl acetate–methanol–water (8:2:8:2, v/v). The chemical structures of the isolated compounds were determined by 1H- and 13C-NMR and ESI-MS. Among the isolated compounds, (6E,12E)-tetradeca-6,12-diene-8,10-diyne-1,3-diol diacetate and selina-4(14),7(11)-dien-8-one increased ARE activity 32.9-fold and 16.6-fold, respectively, without significant cytotoxicity, when 5 µM sulforaphane enhanced ARE activity 27.1-fold. However, atractylenolide I did not increase ARE activity at 100 µM, and showed cytotoxicity at concentrations over 10 µM.

− The methylglyoxal (MGO) trapping constituents from onion (Allium cepa L.) peels were investigated using pre-column incubation of MGO and crude extract followed by HPLC analysis. The peak areas of MGO trapping compounds decreased, and their chemical structures were identified by HPLC-ESI/MS. Among major constituents in outer scale of onion, 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone (2) was more effective MGO scavenger than quercetin (6) and its 4'-glucoside, spiraeoside (3). After 1 h incubation, compound 2 trapped over 90% MGO at a concentration of 0.5 mM under physiological conditions, but compounds 3 and 6 scavenged 45%, 16% MGO, respectively. HPLC-ESI/MS showed that compound 2 trapped two molecules of MGO to form a di-MGO adduct and compounds 3 and 6 captured one molecule of MGO to form mono-MGO adducts, and the positions 6 and 8 of the A ring of flavonoids were major active sites for trapping MGO.

Four new (1 – 4) and one known (5) acylated iridoid glycosides were isolated from the aerial parts of Veronicastrum sibiricum (L.) Pennell. The chemical structures of the isolated compounds were determined to be 3″,4″‐dicinnamoyl‐6‐O‐rhamnopyranosyl‐10‐O‐bergaptol‐5,7‐bisdeoxycynanchoside (1), 3″,4″‐dicinnamoyl‐6‐O‐rhamnopyranosylpaulownioside (2), 2″,4″‐dicinnamoyl‐6‐O‐rhamnopyranosylcatalpol (3), 3″,4″‐dicinnamoyl‐6‐O‐rhamnopyranosylaucubin (4), and 3″,4″‐dicinnamoyl‐6‐O‐rhamnopyranosylcatalpol (5) using spectroscopic techniques. Among these compounds, compound 5 increased antioxidant response element (ARE) luciferase activity.