Isolation of Stilbenoids and Lignans from Dendrobium hongdie

Purpose: To isolate and characterize chemical compounds of biological importance from the whole plant of Dendrobium hongdie. Methods: The whole plants of Dendrobium hongdie was extracted with ethanol (EtOH) and separated using silica gel, Sephadex LH-20 and MCI gel to isolate the pure compounds. Characterization of the isolated compounds was achieved using H-1 and C-13 nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS). Results: Nine compounds including two phenanthrenes, three bibenzyls, a phenanthraquinone, two lignans and a sterol were isolated from the extract. The structures of the compounds were elucidated as nudol (1), gigantol (2), batatasin III (3), tristin (4), moscatin (5), ephemeranthoquinone (6), (-)-syringaresinol (7), liriodendrin (8) and beta-sitosterol (9). Conclusion: Nine compounds have been successfully isolated from D. hongdie for the first time. This plant is a potential source of some useful phytochemicals.