• Natural Product Sciences
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• v.6 no.3
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• pp.135-138
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• 2000

MeOH extract of Cuscuta chinensis seeds was fractionated with n-hexane, EtOAc and BuOH successively, and antioxidant activities were tested for all fractions using DPPH free radical scavenging method. In the tested fractions, EtOAc fraction showed high antioxidant activity$(EC_{50},\;50\;{\mu}g)$ From the EtOAc fraction, five compounds have been isolated. On the basis of spectral data, these compounds were identified as ${\beta}-sitosterol$, methyl 4-hydroxy-3,5-dimethoxycinnamate, ${\beta}-sitosterol-3-O-{\beta}-D-glucopyranoside$, caffeic acid, quercetin, kaempferol and calycopteretin. Among these compounds, ${\beta}-sitosterol$ and ${\beta}-sitosterol-3-O-{\beta}-D-glucopyranoside$ showed no antioxidant activity. $EC_{50}$ values of methyl 4-hydroxy-3,5-dimethoxycinnamate, caffeic acid, quercetin, kaempferol and calycopteretin were 0.6, 8, 19, 17 and $12\;{\mu}g$, respectively.

• Natural Product Sciences
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• v.18 no.1
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• pp.22-25
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• 2012

Five triterpenoids, epifriedelanol (1), friedelin (2), lupeol (3), ${\beta}$-sitosterol (4), daucosterol (5), and one phenyl propanoids ester, trans-docosanoyl ferulate (6) were isolated from the whole parts of Portulaca oleracea. They were determined using a combination of spectroscopic analyses ($^1H-$, $^{13}C$-NMR, and MS data) and evaluated for their cyclooxygenase inhibitory activity. Compound 6 exhibited inhibitory effect with $IC_{50}$ values of $40.2{\mu}M$ and 1.6 mM on COX-1 and COX-2 activities, respectively.