RESUMO
Objective: To study the chemical constituents from the leaves of Ledum palustre and their antitumor activities. Methods: The chemical constituents were isolated and purified by chromatography of silica gel column, recrystallization and HPLC, and their structures were elucidated by spectral analysis. The in vitro cytotoxic activities of the isolated compounds were studied by MTT method. Results: Nine compounds were isolated and identified as ledumone (1), uvaol (2), lepenone (3), α-amyrenone (4), ursolic acid (5), lupeol (6), α-amyrin (7), fern-9(11)-ene-2α,3β-diol (8), and fernenol (9). Conclusion: Compound 1 is new named as ledumone, and compounds 4, 8, and 9 are isolated from Ledum palustre for the first time. Fernane type triterpene 1, 8, and 9 show no significant cytotoxicities against A549 and K562 cells.