Highly Effective and Hydrolytically Stable Vanadium(V) Amino Phenolato Antitumor Agents.

Vanadium(V) oxo complexes with no labile ligands, including six octahedral complexes with pentadentate diaminotris(phenolato) ligands and one pentacoordinate complex with a tetradentate aminotris(phenolato) ligand, were synthesized in high yields. All octahedral complexes demonstrated high hydrolytic stability with no signs of decomposition after days in the presence of water, whereas the pentacoordinate complex decomposed within minutes to release the free ligand, demonstrating the marked impact of coordination number and geometry on the complex electrophilicity. All complexes showed marked cytotoxicity toward human colon HT-29 and ovarian OVCAR-3 cells.

Anticancer metal complexes: synthesis and cytotoxicity evaluation by the MTT assay.

Titanium (IV) and vanadium (V) complexes are highly potent anticancer agents. A challenge in their synthesis refers to their hydrolytic instability; therefore their preparation should be conducted under an inert atmosphere. Evaluation of the anticancer activity of these complexes can be achieved by the MTT assay.

Highly cytotoxic vanadium(V) complexes of salan ligands; insights on the role of hydrolysis.

Vanadium(V) oxo complexes with tetradentate diamine bis(phenolato) "salan" ligands of the type LVO(OiPr) (L is salan) with different steric and electronic substitutions at the ortho and para positions to the binding phenolato moiety were synthesized and their hydrolytic stability and cytotoxicity were analyzed. With one exception bearing large steric groups, all complexes examined displayed marked cytotoxic activity, comparable to, and often higher than, that of cisplatin. While the hydrolytic stability changed significantly depending on the substituent at the ortho position relative the O-donor with little effect of para substitutions, the cytotoxic activity largely was not affected, and high cytotoxicity was recorded also for relatively unstable complexes.

The mechanism of iron homeostasis in the unicellular cyanobacterium synechocystis sp. PCC 6803 and its relationship to oxidative stress.

In this article, we demonstrate the connection between intracellular iron storage and oxidative stress response in cyanobacteria. Iron is essential for the survival of all organisms. However, the redox properties that make iron a valuable cofactor also lead to oxidative interactions, resulting in the formation of harmful radicals.