Platinum(IV)-azido monocarboxylato complexes are photocytotoxic under irradiation with visible light.

Complexes trans,trans,trans-[Pt(N3)2(OH)(OCOR)(py)2] where py = pyridine and where OCOR = succinate (1); 4-oxo-4-propoxybutanoate (2) and N-methylisatoate (3) have been synthesized by derivation of trans,trans,trans-[Pt(OH)2(N3)2(py)2] (4) and characterised by NMR and EPR spectroscopy, ESI-MS and X-ray crystallography. Irradiation of 1-3 with green (517 nm) light initiated photoreduction to Pt(ii) and release of the axial ligands at a 3-fold faster rate than for 4. TD-DFT calculations showed dissociative transitions at longer wavelengths for 1 compared to 4.

Photoactivatable platinum anticancer complex can generate tryptophan radicals.

l-Tryptophan (Trp), melatonin (MLT) and the Trp-peptide pentagastrin quenched the formation of azidyl radicals generated on irradiation of the anticancer complex trans,trans,trans-[Pt(pyridine)2(N3)2(OH)2] with visible light, giving rise to C3-centred indole radicals which were characterized for Trp and MLT using an EPR spin-trap; indole, together with azidyl and hydroxyl radicals, have potential roles in a multitargeting mechanism of action against resistant cancers.

The potent anti-cancer activity of Dioclea lasiocarpa lectin.

The lectin DLasiL was isolated from seeds of the Dioclea lasiocarpa collected from the northeast coast of Brazil and characterized for the first time by mass spectrometry, DNA sequencing, inductively coupled plasma-mass spectrometry, electron paramagnetic resonance, and fluorescence spectroscopy. The structure of DLasiL lectin obtained by homology modelling suggested strong conservation of the dinuclear Ca/Mn and sugar-binding sites, and dependence of the solvent accessibility of tryptophan-88 on the oligomerisation state of the protein. DLasiL showed highly potent (low nanomolar) antiproliferative activity against several human carcinoma cell lines including A2780 (ovarian), A549 (lung), MCF-7 (breast) and PC3 (prostate), and was as, or more, potent than the lectins ConBr (Canavalia brasiliensis), ConM (Canavalia maritima) and DSclerL (Dioclea sclerocarpa) against A2780 and PC3 cells.

[Fe(CN)5(isoniazid)](3-): an iron isoniazid complex with redox behavior implicated in tuberculosis therapy.

Tuberculosis has re-emerged as a worldwide threat, which has motivated the development of new drugs. The antituberculosis complex Na3[Fe(CN)5(isoniazid)] (IQG607) in particular is of interest on account of its ability to overcome resistance. IQG607 has the potential for redox-mediated-activation, in which an acylpyridine (isonicotinoyl) radical could be generated without assistance from the mycobacterial KatG enzyme.

De novo generation of singlet oxygen and ammine ligands by photoactivation of a platinum anticancer complex.

Worth the excitement: Highly reactive oxygen and nitrogen species are generated by photoactivation of the anticancer platinum(IV) complex trans,trans,trans-[Pt(N3 )2 (OH)2 (MA)(Py)] (MA=methylamine, Py=pyridine). Singlet oxygen is formed from the hydroxido ligands and not from dissolved oxygen, and ammine ligands are products from the conversion of azido ligands to nitrenes. Both processes can induce oxidation of guanine.

Targeted delivery of platinum-based anticancer complexes.

The most widely used anticancer drugs are platinum-based. Their efficacy might be improved by carriers which can transport large numbers of Pt centres, shield the drug from premature activation, and/or deliver Pt specifically to cancer cells using vectors which recognise specific targets. We describe recent progress using functionalized carbon nanotubes (CNTs) and nanorods, hollow Prussian blue (HPB), magnetic iron oxide and gold nanoparticles, liposomes, nanogels and polymers, as well as active targeting by conjugation to biodegradable proteins and peptides (e.

Tryptophan switch for a photoactivated platinum anticancer complex.

The octahedral Pt(IV) complex trans,trans,trans-[Pt(N(3))(2)(OH)(2)(py)(2)] (1) is potently cytotoxic to cancer cells when irradiated with visible (blue) light. We show that the acute photocytotoxicity can be switched off by low doses (500 μM) of the amino acid l-tryptophan. EPR and NMR spectroscopic experiments using spin traps show that l-Trp quenches the formation of azidyl radicals, probably by acting as an electron donor.

Phosphorus leaching in manure-amended Atlantic Coastal Plain soils.

Targeting the sources of phosphorus (P) and transport pathways of drainage from agricultural land will assist in the reduction of P loading to surface waters. Our research investigated the vertical movement of P from dairy manure and broiler litter through four Atlantic Coastal Plain soils. A randomized split-plot design with two main-plot tillage treatments (no tillage [NT] and chisel tillage [CH]) and five manure P rate split-plot treatments was used at each location.