• Natural Product Sciences
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• v.17 no.3
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• pp.206-211
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• 2011

High-performance liquid chromatography coupled to an online $ABTS^+$-based assay (online HPLC-$ABTS^+$) system was used to determine the principal antioxidants in Cudrania tricuspidata fruits. Six prenylated isoflavonoids (1 - 6) were isolated from C. tricuspidata fruits according to the online HPLC-$ABTS^+$ system. The structures of isolated compounds, alpiniumisoflavone (1), 6,8-diprenylorobol (2), 6,8-diprenylgenistein (3), pomiferin (4), 4'-methylalpiniumisoflavone (5), and osajin (6) were identified by their retention time, UV spectra, ESI-MS, and NMR data. Among these compounds, 6,8-diprenylorobol (2) and pomiferin (4) reduced A2E photooxidation in a dose dependent manner.

• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.414-419
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• 2010

Hyphenated-HPLC techniques combine the separation power of HPLC with the structural and bioactivity information provided by NMR, ESI/MS, and an on-line antioxidant screening system. The major advantages over the traditional off-line techniques are rapidity and efficiency. In this study, we used hyphenated HPLC techniques including online HPLC-ABTS, LC-NMR, and LC-MS todirectly identify the major antioxidants of safflower (Carthamus tinctorius L.) seeds. The results demonstrated that the major antioxidant compounds from on-line HPLC-ABTS analysis were identified as 8'-hydroxyarcgenin-4'-O-$\beta$-D-glucoside, N-(p-coumaroyl) serotonin, and N-feruloylserotonin. Among them, N-feruloylserotonin accounted for almost 50% of the ABTS radical scavenging activity of the total extract. The results demonstrate that HPLC hyphenated techniques can be used to rapidly screen and structurally identify antioxidants from crude plant extracts.