Two new cadinene-type sesquiterpene glycosides from Dendrobium findlayanum

Two new and one known cadinene-type sesquiterpene glycosides, findlayanosides A-B (1-2) and dendronobiloside D (3), were isolated from the stems of Dendrobium findlayanum. This is the first report that cadinene-type sesquiterpene glycosides were isolated from D. findlayanum. The structures of compounds 1 and 2 were elucidated by extensive spectroscopic analyses, and their absolute configurations were confirmed by electronic circular dichroism (ECD) calculations. The obtained compounds were evaluated for their cytotoxicity against HL-60, SMMC-7721, A-549 and MCF-7 human cancer cells, and no obvious cytotoxic activity was observed at the concentration of 25 μΜ.