Abstract
The extraction yield of the methanolic extracts and 19${\alpha}$-hydroxyursane-type triterpenoid (19${\alpha}$-HUT) fraction were investigated in the unripe and ripe fruits and the leaves of the four Rubus plants (Rubus coreanus, R. crataegifolius, R. phoenicolasius, R. pungens var. oldhami) to develop the biomaterial 19${\alpha}$-HUT mixture as functional foods. Thin layer chromatogaphy-Densitometer (TLC-DM) was used to analyze the individual quantity of 19${\alpha}$-HUTs using standard compounds (euscaphic acid, tormentic acid, 23-hydroxytormentic acid, kaji-ichigoside F$_1$, rosamultin, niga-ichigoside F$_1$). The content of methanolic extract of the fruits were higher in the ripe stage than in the unripe stage whereas the content of 19${\alpha}$-HUT mixture varied with each Rubus species. The Rubus plants containing the highest amount of 19${\alpha}$-HUTs in the leaves were R. coreanus, R. phoenicolasius and R. pungens var. oldhami while only R. cratagefolius showed the highest content in the ripe fruits. The mean of total genin content of 19${\alpha}$-HUTs was 0.94 mg/g; that of the glycosides was 0.60 mg/g. The genin quantity was found in the order of 23-hydroxytormentic acid> euscaphic acid> tormentic acid; the glycoside was observed in the order of niga-ichig-oside F$_1$> kaji-ichigoside F$_1$> rosmaultin, by which the biosynthetic pathway of 23-hydroxytormentic acid and its glucoside niga-ichigoside F$_1$ via the intermediates tormentic acid and/or rosamultin was presumed. It is also suggested that the ripe fruits of R. crataegifolius will be desirable to use as functional foods rather than unripe fruits.
