Dendronone, a new phenanthrenequinone from Dendrobium cariniferum

The stems of several Dendrobium species of the Orchidaceae, used as health foods and nutrients, are rich sources of aromatics, Such as bibenzyls, phenanthrenes, fluorenones and simple aromatic acids and esters with antitumour, antioxidant and antimutagenic activities. From the chloroform extract of the whole plant of Dendrobium cariniferum, a new phenanthrenequinone, dendronone, was isolated. Its structure was identified as 5-hydroxy-7-methoxy-9,10-dihydro-1,4-phenanthrenequinone, based on extensive spectroscopic studies, including HRESIMS, EIMS, H-1 NMR, C-13 NMR. DEPT, H-H COSY, HSQC, HMBC and NOESY spectra. In this paper, we described the isolation procedure and the structural elucidation of this new compound, as well as the detection of gigantol and batatasin III by co-chromatography with authentic standards. (C) 2008 Elsevier Ltd. All rights reserved.