title: Synthesis, molecular structure, solution equilibrium, and antiproliferative activity of thioxotriazoline and thioxotriazole complexes of copper II and palladium II.
abstract: Preparations of copper(II) and palladium(II) complexes of 4-amino-5-methylthio-3-(2-pyridyl)-1,2,4-triazole (L(1)) and the copper(II) complex of 1,4-dihydro-4-amino-3-(2-pyridyl)-5-thioxo-1,2,4-triazole (HL) are described. These complexes have been characterized by means of spectroscopy and microanalysis. Molecular structures of HL (1), [CuCl(2)(H(2)L)]Cl.2H(2)O (2a), cis-[CuCl(2)(L(1))] (3), and cis-[PdCl(2)(L(1))] (4) have been determined by single-crystal X-ray diffraction. The HL ligand acts as a N,S bidentate through the thioxo moiety and the exo-amino group whilst the ligand L(1) forms N,N coordination complexes through the pyridine and triazole nitrogen atoms. Speciation in solution of the systems Cu/HL and Cu/L(1) have been determined by means of potentiometry and spectrophotometry as well as for the Cu/L(1)/A (HA=glycine) system in order to determine species present at physiological pH. Antiproliferative activity of these complexes and their ligands was evaluated, using the AlamarBlue Assay, on normal human fibroblasts (HF) and human fibrosarcoma tumor (HT1080) cells. The copper compounds cis-[CuCl(2)(H(2)L)]Cl and cis-[CuCl(2)(L(1))] exerted significant antiproliferative activity of both normal and neoplastic cells; although dose-response experiments revealed that the HT1080 cell line was more sensitive to the tested drugs than normal fibroblasts.
authors.affiliation: Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica, Università degli Studi di Parma, Parco Area delle Scienze 17a, 43100 Parma, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Dallavalle
authors.forename: Francesca
authors.initials: F
authors.lastname: Gaccioli
authors.forename: Renata
authors.initials: R
authors.lastname: Franchi-Gazzola
authors.forename: Maurizio
authors.initials: M
authors.lastname: Lanfranchi
authors.forename: Luciano
authors.initials: L
authors.lastname: Marchiò
authors.forename: Maria Angela
authors.initials: MA
authors.lastname: Pellinghelli
authors.forename: Matteo
authors.initials: M
authors.lastname: Tegoni
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D003300:Copper / Q000737:chemistry; D018360:Crystallography, X-Ray; D006801:Humans; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry* / Q000494:pharmacology; D010165:Palladium / Q000737:chemistry; D012996:Solutions; D014230:Triazoles / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D009942:Organometallic Compounds; D012996:Solutions; D014230:Triazoles; D010165:Palladium; D003300:Copper