Superoxide dismutase and polyphenol oxidase biomimetic activities of Copper (II) 3,5 diisopropylsalicylate complexes with histamine and cimetidine

Abstract

Abstract - Copper(II) with 3,5-diisopropylsalicylate, Cu2(3,5-DIPS)4, is a binuclear tetracarboxylate–bridged complex. This tan solid has been found to have several pharmacological effects which include radioprotectant, radiorecovery, anti-inflammatory, anti-convulsant, anti-diabetic, anti-ulcer, anti-cancer and analgesic activities. Some of these pharmacological activities are enhanced in the presence of ancillary nitrogen donor ligands such as imidazoles, diimines and amines. These pharmacological effects of Cu(II) salicylate type complex may be attributed to the anti-oxidative activities against the reactive oxygen species, especially superoxide radical anion (O .2 ), which contribute to the cause of these diseases. Histamine (Hst) and cimetidine (Cmt) are biologically active ligands and have imidazole and amine nitrogen type ligands and can chelate with metal ions. Cimetidine is a drug that has been used as a powerful histamine H2-receptor antagonist in the treatment of peptic ulcer. Special interest has been devoted to the interaction of these ligands with 2 copper(II) ion, since some clinical results support that these interactions play important role in vivo. We will present our results on the synthesis and spectral characterization of mononuclear ternary complexes of the binary copper(II) 3,5-diisopropylsalicylate, Cu2(3,5-DIPS)4, complex with histamine and cimetidine and our results on their activities as superoxide dismutase (SOD) mimics. The polyphenol catalytic activities of these binary and ternary complexes for catecholase oxidation of 3,5-di-tert-butylcatechol (DTBCH2) to corresponding o-benzoquinone(DTBQ) and for oxidative dealkylation of a hindered 2,4,6- tri-tert-butylphenol (TTBP) will also be presented.