Triterpenoids from Camellia japonica and Their Cytotoxic Activity

From the ethyl acetate fraction of the stem bark of Camellia japonica, three new triterpenoids, 3β-O-acetyl-16β-hydroxy-12-oxoolean (6), 3β-O-acetyl-16β-hydroxy-11-oxoolean-12-ene (7), and 3β-O-acetyl-16β-hydroxyolean-12-ene (8), along with seven known compounds, 3α-hydroxy-1-oxofriedelan (1), friedelin (2), 3β-friedelanol (3), canophyllol (4), 3-oxofriedelan-1(2)-ene (5), β-amyrin (9), camellenodiol (10), and camelledionol (11) were isolated. Their structures were established on the basis of spectroscopic analysis and chemical evidence. The isolated compounds were tested in vitro for their cytotoxic activities against the A549, LLC, HL-60 and MCF-7 cancer cell lines. Among them, compound 8 showed cytotoxicity against LLC and HL-60 cancer cell lines with IC50 values of 25.2 and 21.7 μM, respectively. Camellia japonica L. (Theaceae) is widely cultivated as an ornamental or garden tree in Korea. The seeds of C.japonica have been used as a stomachic and anti-inflammatory in Chinese folk medicine and also as an oil material, 1) while the flowers and flower buds of this plant have been prescribed in Chinese traditional preparations for treatment of hematemesis and "Oketsu" syndrome (blood stagnation), blood vomiting and bleeding due to internal and external injury, and also as an anti-inflammatory, tonic, and stomachic. 1, 2)