Comparative antioxidant activity and HPLC profiles of some selected Korean thistles

As yet, no comparative analyses have been conducted regarding the comparative antioxidant activities and HPLC profiles of thistles distributed in Korea. Thus, this study was performed in order to evaluate the antioxidant potentials of seven Korean thistles: Cirsium lineare, Cirsium chanroenicum, Cirsium setidens, Cirsium japonicum var. ussuriense, Cirsium nipponicum, Cirsium pendulum and Carduus crispus, via peroxynitrite and DPPH free radical assays. Among seven Korean thistles, Carduus crispus exhibited the most significant antioxidant activity in both DPPH assay and peroxynitrite. In order to characterize the compounds contained in Korean thistles, we conducted HPLC analyses on the following ten flavonoids: luteolin-5-glucoside (1), luteolin-7-glucoside (2), apigenin-7-glucoside (3), hispidulin-7- neophesperidoside (4), apigenin-7-glucuronide (5), cirsimarin (6), pectolinarin (7), luteolin (8), apigenin (9) and acacetin (10). The results of our HPLC analyses indicated the presence of pectolinarin in the whole plants of C. setidens, C. lineare, C. nipponicum, C. pendulum, the aerial and underground parts of C. japonicum var. ussuriense, and the aerial parts of C. chanroenicum. Moreover, we were able to identify hispidulin-7-neophesperidoside and luteolin-7-glucoside in the whole plants of Carduus crispus, acacetin in the aerial parts of C. chanroenicum, cirsimarin in C. lineare.