Stilbenes, phenanthrenes and antiproliferative activity of Cattleya intermedia .

The phytochemical study of Cattleya intermedia (Orchidaceae) led to the isolation of two new stilbenoids and one new 9,10-dihydrophenanthrene, 4',5-dihydroxy-2',3-dimethoxy-dihydrostilbene ( 1 ), 3,6'-dihydroxy-4'-methoxy-dihydrostilbene ( 2 ) and 1,2,6-trihydroxy-3,8-dimethoxy-9,10-dihydrophenanthrene ( 3 ), named cattleymediol, cattleyol and phenanmediol, respectively, in addition to other five known compounds ( 4-8 ). The structural elucidations of the isolated compounds were carried out through the analyses of the one-dimensional 1 H, 1 ³C and NOE NMR spectra, and the 2D HSQC, HMBC, COSY and NOESY spectra, besides high-resolution mass spectrometry. In addition to this, the crude extract and its main fractions were analysed by ultra-high performance liquid chromatography coupled to high resolution mass spectrometry (UHPLC-QTOF-MS/MS), leading to the putative identification of several other compounds, including flavonoids and organic acids derivatives. Finally, the main fractions of the crude extract, and the pure compounds cattleymediol ( 1 ) and lusiantridine ( 7 ), had their antiproliferative activities evaluated against human cancerous HeLa and non-cancerous VERO cells.