Triterpenoids from the Roots of Camellia oleifera C.Abel and Their Cytotoxic Activities

Three new triterpenoids, 21β,22α-diangeloyloxy-3β,15α,16α,28-tetrahydroxyolean-12-en-23-al (1), 21β-angeloyloxy-3β,15α,16α,28-tetrahydroxy-22α-(2-methylbutanoyloxy)olean-12-en-23-al (2), and 21β-angeloyloxy-3β,16α,28-trihydroxy-22α-(2-methylbutanoyloxy)olean-12-en-23-al (3), along with six known triterpenoids, were isolated from the roots of Camellia oleifera C.Abel. The structures of compounds 1–3 were elucidated on the basis of spectroscopic analyses. Moreover, all compounds isolated were evaluated for their cytotoxic activities by MTT (=3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay.