DNA modification by oxovanadium(IV) complexes of salen derivatives

Abstract

Oxovanadium(IV) complexes of hydroxysalen derivatives have been prepared and tested as DNA reactive agents. The nuclease activity has been investigated under oxidative or reducing conditions, on the basis of the various oxidation states of vanadium: V(III), V(IV) and V(V). In the absence of an activating agent, none of the compounds tested was able to induce cleavage of DNA, whereas in the presence of mercaptopropionic acid (MPA) or Oxone the four complexes induced DNA modifications. Under both conditions, the para-hydroxy complex was found to be the most active compound. Reaction of these salen complexes with DNA occurs essentially at guanine residues and is more efficient in the presence of Oxone than under reducing conditions. The extent of Oxone-mediated DNA oxidation by the four vanadyl complexes was clearly superior to VOSO(4) and was observed without piperidine treatment. EPR studies provided information on the reactive metal-oxo species involved under each conditions and a mechanism of reaction with DNA is discussed.

Cytotoxic and genotoxic effect in RTG-2 cell line exposed to selected biocides used in the disinfection of cooling towers

“…However, no significant differences respects to control were obtained when RTG-2 cells were exposed to selected Oxone Ò concentrations, obtaining a maximal SSF value of 0.070. Although the genotoxic effect in vertebrates, induced by exposures to Oxone Ò alone, are not known, different authors have been reported that the formation in vitro of different metal complex, generated from oxidation with this compound, induced DNA damage (Hegedus et al 2003;Verquin et al 2004), or binds to single-stranded DNA and causes strand scission at specific guanine sites (Guan et al 1993). However, when Young and Setlow (2004) determine the inhibition mechanisms induced by Oxone Ò on Bacillus subtilis spore, their results indicate that these spores did not accumulate DNA strand breaks and were not mutagenized, and therefore, Oxone Ò do not kill B. subtilis spores by DNA damage.…”

DNA cleavage activity of VIVO(acac)2 and derivatives

“…In the same publication, Heater et al report a strong nuclease activity for the V IV -phen complex. In 2004, V IVcomplexes with hydroxysalen ligands showed nuclease activity, in the presence of an activating agent, either a reducing one like mercaptopropioic acid (MPA) or an oxidizing one such as oxone (KHSO 5 ) [15], but the authors did not establish the actual active vanadium species. More recently, several V complexes with photocleavage activity were proposed as promising compounds for cancer phototherapy.…”

Spectral characterization and DNA binding properties of lanthanide(III) complexes with 2-acetylpyridine isonicotinoylhydrazone (APINH)

“…Heterocyclic hydrazones as well as their metal complexes gained importance because of their pharmacological properties [18][19][20]. Metal complexes of isonicotinoylhydrazones exhibit antitumour [21] and antibacterial activity [22]. There is also much interest in the development of artificial nucleases.…”