This work presents the synthesis, characterization, and application of several new metal(I) complexes with trifluoromethylpyridine-containing N-heterocyclic carbene (NHC) ligands. The metal of choice was gold(I) for compounds 7 -10, rhodium(I) for 11 -12, and iridium(I) for 13 -14, respectively. The trifluoromethylpyridine moiety was incorporated, along with other biologically active moieties, with the intention of modifying the lipophilicity of the complexes, so that the transport of the active units (M-NHC) through the cell wall barrier is facilitated. The biological activity of the complexes was investigated. In vitro assessment of antitumor activity in a panel of 12 human tumor cell lines by a monolayer assay revealed good potency (mean IC 50 12.6 lM) and tumor selectivity for one compound. The solid-state structures of two solvates of compound 7, one with MeOH and one with THF, were determined by X-ray diffraction analysis.

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In Southeast Europe, the ethnomedicinal use of Helleborus species has a very long tradition. Cardiac steroids (Hellebrin), cysteine-rich proteins (Hellethionins) and several steroidal saponins have been identified in these plants. Aim of the present work was to investigate the amino acid composition of native extracts from the root and rootstock of Helleborus purpurascens. The amino acids have been identified by the GC-MS technique on the previously derivatised (Phenomenex Faast Kit) extract samples by comparison with the mass spectra and retention-time of the standards. A remarkable finding was a relatively intensive peak attributed to the non-proteinogenic Pipecolic acid (Pic). A cyclisation of the derivatised glutamine was observed during the GC measurement and a mechanistic pathway is described. Samples of the extract and of some isolated fractions have also been tested on; altogether 12 cancer cell lines aimed to identify further potentially cytostatic components which should be less toxic than Hellebrin. The finding of one Hellebrin-free fraction (IC = 0.007 mg/L) with higher cytotoxicity than Hellebrin (IC = 0.008 mg/L) is remarkable.