A New Isoflavone Glycoside from the Stems of Tilia taquetii Schneider

摘要

Tilia taquetii Schneider is a deciduous tree belonging to a family Tiliaceae. The genus Tilia comprises six species distributing in Korea and T. taquetii is known to be Korean endemic plant. Because its lumber has highly durable properties, this tree has long been used as raw materials for household furniture. The flowers of this tree have been used as the folk medicine for the alleviation of flu symptoms in Korea. However, as far as we know, no report has been published so far on this plant either in biological or phyto-chemical viewpoint. As our continuing program searching for bioactive compounds from plants collected in Jeju Island, we became interested in the ethanol extract of T. taquetii stems in which DPPH radical scavenging activities were observed. This led us to undertake a chemical investigation on the extract to identify the active constituents. As the result, we herein report the isolation and characterization of a new compound, orobol 4'-O-β-glucopyranoside (1) together with four known compounds, 3'-O-methylorobol (2), cleomiscosin A (3), cleomiscosin B (4), and oleic acid (5) (Figure 1).