• Korean Journal of Pharmacognosy
• /
• v.38 no.3 s.150
• /
• pp.227-233
• /
• 2007

Seven compounds were isolated from the n-BuOH soluble fraction of stem of Rhododendron mucronulatum as cytotoxic principles against brine shrimp lethality test. On the basis of spectral data, seven compounds were identified as (-)-catechin (1), (+)-epicatechin (2), taxifolin (3), scopoletin (4), quercetin (5), $taxifolin-3-O-{\alpha}-L- arabinopyranoside$ (6), and astragalin (7). Among tested compounds, $taxifolin-3-O-{\alpha}-L-arabinopyranoside$ (6) exhibited potent activity with $LC_{50}$ value at 4.6 ${\mu}g/ml$.

• Natural Product Sciences
• /
• v.11 no.2
• /
• pp.97-102
• /
• 2005

From the n-BuOH soluble traction of the 70% aqueous acetone extract of Rhododendron mucronulatum stem, twelve compounds were isolated. On the basis of spectral data, they were identified as scopoletin (1), (+)-taxifolin (2), quercetin (3), (-)-catechin (4), (+)-epicatechin (5), scopolin (6), lyoniside (7), ssioriside (8), fraxin (9), $(+)-lyoniresinol-3{\alpha}-O-{\beta}-D-glucopyranoside$ (10), $(+)-taxifolin-3-O-{\alpha}-L-arabinopyranoside$ (11), and astragalin (12), respectively. All isolated compounds were tested antioxidant activity against 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical. Compounds 2 and 3 showed the potent antioxidant activity, and compounds 5, 8, and 11 showed moderate activity.