• Korean Journal of Pharmacognosy
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• v.38 no.1
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• pp.31-36
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• 2007

In this study, we have investigated the antioxidant activities of the leaves of Smilax china Linne in order to find the antioxidant substances which has an scavenging effect of reactive oxygen species (ROS) from natural products. As a result, EtOAc and n-BuOH extracts of the leaves of Smilax china Linne exhibited potent antioxidant effect on various antioxidant experiment. The major components of antioxidant activity were isolated from EtOAc and n-BuOH extracts of the leaves of Smilax china Linne. Their structure of compounds were identified as kaempferol-7-O-${\alpha}$-L-rhamnopyranoside and kaempferol-3,7-O-${\alpha}$-L-dirhamnopyranoside by spectroscopic evidence, respectively. Antioxidant activities were observed in kaempferrol-7-O-${\alpha}$-L-rhamnopyranoside at 23 ${\mu}g$ and in kaempferol-3,7-O-${\alpha}$-L-dirhamnopyranoside at 27 ${\mu}g$ as concentration of DPPH 50% reduction.

• Natural Product Sciences
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• v.18 no.2
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• pp.111-115
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• 2012

In the course of screening for antioxidant compounds by measuring the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging effect and superoxide quenching activity, methanol extract of Cyperus flaccidus (Cyperaceae) was found to show potent antioxidant activities. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of ten compounds, kaempferol-3,7-O-${\alpha}$-L-dirhamnopyranoside (1), caffeic acid (2), quercetin-3-O-${\alpha}$-L-rhamnopyranosyl($1{\rightarrow}6$)-${\beta}$-D-glucopyranoside (3), kaempferol-3-O-${\alpha}$-L-rhamnopyranoside (4), quercetin-3-O-${\alpha}$-L-rhamnopyranoside (5), luteoiln-7-O-${\beta}$-D-glucopyranoside (6), kaempferol-3-O-${\alpha}$-L-rhamnopyranosyl($1{\rightarrow}6$)-${\beta}$-D-glucopyranoside (7), luteoiln (8), quercetin (9) and quercetin-3-O-${\beta}$-D-glucuronide (10). Their structures were elucidated by spectroscopic studies. Compounds 1 - 10 were isolated for the first time from this plant. Among them, compounds 2, 8 and 9 showed the significant radical scavenging effects on DPPH, and the potent xanthine-originated superoxide quenching activities.