The study investigated the chemical constituents from the whole herb of Carpesium cernuum. Three new diterpenoids were isolated from the whole herb of C. cernuum by column chromatography on silica gel, Sephadex LH-20, and semi-preparative HPLC. Their structures were identified by MS, NMR and other spectral techniques. The isolates were identified as(5Z)-2-oxo-2, 10, 14-trimethylhexadeca-5, 13-diene-11α, 18-diol(1),(2E, 10E)-7-[(acetyloxy)methyl]-3, 11, 15-trimethylhexadeca-2, 10, 14-triene-1, 12α-diol(2),(2E, 6Z)-3, 11, 15-trimethylhexadeca-2, 6, 14-triene-1, 12α, 19-triol(3), respectively. The cytotoxic activity of compounds 1-3 were investigated with DU-145, MCF-7, and A549 cells by MTT. The results showed that compound 1 and 3 had certain inhibitory effects on MCF-7 cells, with the inhibition rates of 45.06% and 29.40%, respectively.
Keywords: Carpesium cernuum; chemical constituent; cytotoxicity activity; diterpenoid; structural identification.