title: New uses for old drugs: attempts to convert quinolone antibacterials into potential anticancer agents containing ruthenium.
abstract: Continuing the study of the physicochemical and biological properties of ruthenium-quinolone adducts, four novel complexes with the general formula [Ru([9]aneS3)(dmso-κS)(quinolonato-κ(2)O,O)](PF6), containing the quinolones levofloxacin (1), nalidixic acid (2), oxolinic acid (3), and cinoxacin (4), were prepared and characterized in solid state as well as in solution. Contrary to their organoruthenium analogues, these complexes are generally relatively stable in aqueous solution as substitution of the dimethylsulfoxide (dmso) ligand is slow and not quantitative, and a minor release of the quinolonato ligand is observed only in the case of 4. The complexes bind to serum proteins displaying relatively high binding constants. DNA binding was studied using UV-vis spectroscopy, cyclic voltammetry, and performing viscosity measurements of CT DNA solutions in the presence of complexes 1-4. These experiments show that the ruthenium complexes interact with DNA via intercalation. Possible electrostatic interactions occur in the case of compound 4, which also shows the most pronounced rate of hydrolysis. Compounds 2 and 4 also exhibit a weak inhibition of cathepsins B and S, which are involved in the progression of a number of diseases, including cancer. Furthermore, complex 2 displayed moderate cytotoxicity when tested on the HeLa cell line.
authors.affiliation: Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana, Slovenia.
authors.forename: Jakob
authors.initials: J
authors.lastname: Kljun
authors.forename: Ioannis
authors.initials: I
authors.lastname: Bratsos
authors.forename: Enzo
authors.initials: E
authors.lastname: Alessio
authors.forename: George
authors.initials: G
authors.lastname: Psomas
authors.forename: Urška
authors.initials: U
authors.lastname: Repnik
authors.forename: Miha
authors.initials: M
authors.lastname: Butinar
authors.forename: Boris
authors.initials: B
authors.lastname: Turk
authors.forename: Iztok
authors.initials: I
authors.lastname: Turel
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D002403:Cathepsins / Q000037:antagonists & inhibitors; D004247:DNA / Q000378:metabolism; D004996:Ethidium / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D015363:Quinolones / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000378:metabolism; D014867:Water / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D009942:Organometallic Compounds; D015363:Quinolones; D014867:Water; D012710:Serum Albumin, Bovine; D012428:Ruthenium; D004247:DNA; C427203:calf thymus DNA; D002403:Cathepsins; D004996:Ethidium