• Korean Journal of Pharmacognosy
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• v.43 no.3
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• pp.201-205
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• 2012

In the course of screening pancreatic lipase inhibitory activity, total methanolic extract and EtOAc-soluble fraction of Duchesnea chrysantha showed significant inhibitory activity. Further fractionation and isolation of the EtOAc-soluble fraction resulted in five compounds, which were identified as trans-tiliroside (1), isovitexin (2), kaempferol-8-O-${\beta}$-glucoside (3), kaempferol-3-O-${\beta}$-glucoside (4) and quercetin-3-O-${\beta}$-glucoside (5). All the five flavonoids derivatives were first reported from this plant but showed weak inhibitory effects on pancreatic lipase activity.

• Natural Product Sciences
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• v.21 no.3
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• pp.162-169
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• 2015

Hamamelis japonica (Hamamelidaceae), widely known as Japanese witch hazel, is a deciduous flowering shrub that produces compact clumps of yellow or orange-red flowers with long and thin petals. As a part of our ongoing search for phenolic constituents from this plant, eleven phenolic constituents including six flavonol glycosides, a chalcone glycoside, two coumaroyl flavonol glycosides and two galloylated compounds were isolated from the flowers. Their structures were elucidated as methyl gallate (1), myricitrin (2), hyperoside (3), isoquercitrin (4), quercitrin (5), spiraeoside (6), kaempferol 4'-O-β-glucopyranoside (7), chalcononaringenin 2'-O-β-glucopyranoside (8), trans-tiliroside (9), cis-tiliroside (10), and pentagalloyl-O-β-D-glucose (11), respectively. These structures of the compounds were identified on the basis of spectroscopic studies including the on-line LCNMR-MS and conventional NMR techniques. Particularly, directly coupled LC-NMR-MS afforded sufficient structural information rapidly to identify three flavonol glycosides (2 - 4) with the same molecular weight in an extract of Hamamelis japonica flowers without laborious fractionation and purification step. Cytotoxic effects of all the isolated phenolic compounds were evaluated on HCT116 human colon cancer cells, and pentagalloyl-O-β-D-glucose (11) was found to be significantly potent in inhibiting cancer cell growth.