Biofilm inhibition by a new Mn(II) complex with sulfamethoxazole: Synthesis, spectroscopic characterization and crystal structure

ALEJANDRO DI SANTO; DIEGO M. GIL; FERNANDO POMIRO; OSCAR E. PIRO; GUSTAVO A. ECHEVERRÍA; MARIO ARENA; CONSTANZA LUCIARDI; RAÚL E. CARBONIO; AÍDA BEN ALTABEF

INORGANICA CHIMICA ACTA

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2015 vol. 436 p. 16 - 33

0020-1693

The reaction in alkaline aqueous solution between sulfamethoxazole (SMX) and manganese (II) chlorideproduces colorless crystals with formula [Mn(H2O)6]0.5[Mn(SMX)3], which was characterized by UV?Vis,IR and Raman spectroscopy and thermal analysis. The crystal structure of [Mn(H2O)6]0.5[Mn(SMX)3] complexhas been solved by X-ray diffraction methods. It crystallizes in the cubic Pa-3 space group witha = 19.5476(1) Å, and Z = 8 molecules per unit cell. [Mn(SMX)3] complex is at a crystallographic specialposition of C3 symmetry with the Mn(II) ion cis-coordinated to three equivalent sulfamethoxazole moleculesacting as bidentate ligands in a propeller-like conformation. [Mn(H2O)6]2+ hydrate ion is at crystalspecial position of S6 symmetry with the metal in an almost perfect octahedral coordination with sixwater molecules. At 100 lg/mL Mn(H2O)6]0.5[Mn(SMX)3] and SMX, inhibited the Staphylococcus aureusbiofilm formation by 92% and 54%, respectively. However, at the same concentrationMn(H2O)6]0.5[Mn(SMX)3] and SMX inhibited the planktonic bacterial growth by 52% and 81%, respectively.The Mn(II) complex inhibited the biofilm formation in values higher than 35% at the concentration0.5 lg/mL. These results suggest that the metal complex [Mn(H2O)6]0.5[Mn(SMX)3] is a good candidatefor the development of new antimicrobial agent acting in part as bactericidal but mainly as antipathogenicagent.