Novel tetraplatinated metalloporphyrin-based photosensitizers (PSs) are reported, which show excellent phototoxic indexes (PIs) up to 5800 against HeLa cells, which is, to the best of our knowledge, the highest value reported for any porphyrin so far. Furthermore, 67Zn isotope labelling allowed the determination of the ratio of zinc to platinum inside the cells using ICP-MS.
View Article and Find Full Text PDFA new method for the post-synthetic modification of nucleic acids was developed that involves mixing a phenyl triazolinedione (PTAD) derivative with DNA containing a vinyl nucleobase. The resulting reactions proceeded through step-wise mechanisms, giving either a formal [4+2] cycloaddition product, or, depending on the context of nucleobase, PTAD addition along with solvent trapping to give a secondary alcohol in water. Catalyst-free addition between PTAD and the terminal alkene of 5-vinyl-2'-deoxyuridine (VdU) was exceptionally fast, with a second-order rate constant of 2×10 m s .
View Article and Find Full Text PDFNovel photoactive (metallo)porphyrins were synthesised and characterised. When irradiated with light at a wavelength greater than 600 nm, these porphyrins act as photosensitisers and show high cytotoxicity towards two different human cancer cell lines with IC50 values down to 0.4 μM.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
July 2014
Despite the extensive use of porphyrins in photodynamic therapy (PDT), tetraplatinated porphyrins have so far not been studied for their anticancer properties. Herein, we report the synthesis of such novel platinum-porphyrin conjugates as well as their photophysical characterization and in vitro light-induced anticancer properties. These conjugates showed only minor cytotoxicity in the dark, but IC50 values down to 19 nM upon irradiation with light at 420 nm.
View Article and Find Full Text PDFChiral iron(ii)-bis(isonitrile) complexes catalyse the transfer hydrogenation of aromatic ketones with enantioselectivities up to 91% ee, most likely via hydride transfer through imine intermediates, generated by in situ reduction of the isonitrile ligands, whereas iron acts as a Lewis acid to activate the ketone.
View Article and Find Full Text PDFThe palladium-catalyzed aerobic oxidation of alkenes and especially styrenes (Wacker oxidation) by using chiral pseudo C(2)-symmetrical bis(isonitrile) ligands in the absence of further cocatalysts gives rise to methyl ketones in a highly chemoselective manner. The palladium bis(isonitrile) catalyst was characterized by NMR spectroscopy and X-ray structure analysis, revealing a dissymmetric coordination of palladium by the two isonitrile moieties.
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