Linarin, a flavone glycoside was isolated from the leaves of Cirsium albescens, C. japonicum var. australe and C. kawakamii f. variegatum. The leaves of C. hosogawa was also examined and three flavonoids-luteolin, luteolin-7-glucoside and linarin were isolated and identified.
The phytochemical studies on the leaves of some Formosan Cirsium genus plants (Compositae) have been already reported. In the further investigations, the authors carried out four Cirsium species, C. albescens, C japonicum var. australe, C. kawakamii f. variegaturn4 and C. hosogawa. In consequence linarin a flavone glycoside, was isolated from the leaves of these four plants as a common component. In addition to linarin and luteolin-7-glucoside were also isolated from the leaves of C. hosogawa. (Table I).