ABSTRACT
OBJECTIVE: To study the antitumor phenanthrene constituents in Dendrobium nobile.METHODS: A variety of chromatographic techniques were applied to extract, isolate and purify natural products from extract of Dendrobium nobile, their structures were identified on the basis of spectral data. The antitumor activity of these monomers in MCF-7 breast cancer cells was studied by MTT assay in vitro. RESULTS: Nine compounds were isolated from ethyl acetate part in Dendrobium nobile, there were four phenanthrene compounds, which were densiflorol B(1), cypripedin(2), moscatin(3) and 2,4,8-trimethoxy phenanthrene-3,7-diol(4); three coumarin compounds: coumarin(5), moellendorffiline(6) and isopimpinellin(7); one flavanoid: naringenin(8); one phenol: (E)-4-(2-methoxyvinyl) benzene-1,2-diol(9). Compounds 1-3 had good antitumor activities, their IC50 values were 2.99, 5.01 and 72.68 μmol•L-1 respectively. CONCLUSION: The compounds 6, 7, 9 are isolated from the Orchidaceae family for the first time, compounds 1, 2, 4, 5, 8 are isolated from this plant for the first time. Compounds 1-3 can be used as candidates for anti-tumor drugs.