Xanthanolides with antitumour activity from Xanthium italicum.

Bioassay-guided fractionation of a CHCl3 extract of the leaves of Xanthium italicum Moretti led to the isolation of four xanthanolides: xanthatin (1), 4-epixanthanol (2), 4-epi-isoxanthanol (3), and 2-hydroxyxanthinosin (4). Their structures were determined by means of 1D and 2D NMR spectroscopy, including 1H-1H COSY, NOESY, HSQC and HMBC experiments, which resulted in complete and unambiguous 1H and 13C NMR chemical shift assignments. The isolated compounds 1-4 were evaluated for their antiproliferative activities, and were demonstrated to exert significant cell growth inhibitory activity against human cervix adenocarcinoma (HeLa), skin carcinoma (A431), and breast adenocarcinoma (MCF7) cells.

Natural phenanthrenes and their biological activity.

The aim of this review is to survey the various naturally occurring phenanthrene compounds that have been isolated from different plants. Only one review has previously been published on this topic. Gorham (1989) reviewed the structures, biosynthesis, separations and spectroscopy of stilbenes and phenanthrenes.

Phenanthrenes and a dihydrophenanthrene from Tamus communis and their cytotoxic activity.

From the petroleum ether extract of the rhizomes of Tamus communis, the 7-hydroxy-2,3,4,8-tetramethoxyphenanthrene (1) was isolated, together with the known 2,3,4-trimethoxy-7,8-methylenedioxyphenanthrene (2), 3-hydroxy-2,4,-dimethoxy-7,8-methylenedioxyphenanthrene (3), 2-hydroxy-3,5,7-trimethoxyphenanthrene (4) and 2-hydroxy-3,5,7-trimethoxy-9,10-dihydrophenanthrene (5), through cytotoxic assay guidance. The structures were determined by means of HREIMS, (1)H NMR, JMOD and NOESY experiments. The cytotoxic effects of the isolated compounds were tested on cervix adenocarcinoma (HeLa) cells, with the MTT assay.

Cytotoxic phenanthrenes from the rhizomes of Tamus communis.

From the fresh rhizomes of Tamus communis five phenanthrenes (1 - 5) were isolated under the guidance of cytotoxic assays in HeLa cells. The compounds were obtained from the highly active CHCl (3) fraction of the MeOH extract by using multistep chromatographic purifications, including VLC, preparative TLC, HPLC and gel filtration. The compounds were identified by means of EI-mass, UV and NMR spectroscopy as 7-hydroxy-2,3,4-trimethoxyphenanthrene (1), 2,7-dihydroxy-3,4-dimethoxyphenanthrene (nudol) (2), 2,7-dihydroxy-3,4,8-trimethoxyphenanthrene (3), 3,7-dihydroxy-2,4,8-trimethoxyphenanthrene (confusarin) (4), and 3,7-dihydroxy-2,4-dimethoxyphenanthrene (5).