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; RAÚL CARBONIO; AIDA BEN ALTABEF

INORGANICA CHIMICA ACTA

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2015 vol. 436 p. 16 - 22

0020-1693

The reaction in alkaline aqueous solution between sulfamethoxazole (SMX) andmanganese (II) chloride produces colorless crystals with formula [Mn(H2O)6]0.5[Mn(SMX)3],which was characterized by UV-visible, IR and Raman spectroscopy and thermal analysis.The crystal structure of [Mn(H2O)6]0.5[Mn(SMX)3] complex has been solved by X-raydiffraction methods. It crystallizes in the cubic Pa-3 space group with a=19.5476(1) Å, andZ= 8 molecules per unit cell. [Mn(SMX)3]- complex is at a crystallographic special positionof C3 symmetry with the Mn(II) ion cis-coordinated to three equivalent sulfamethoxazolemolecules acting as bidentate ligands in a propeller-like conformation. [Mn(H2O)6]2+hydrate ion is at crystal special position of S6 symmetry with the metal in an almostperfect octahedral coordination with six water molecules. At 100 μg/mLMn(H2O)6]0.5[Mn(SMX)3] and SMX, inhibited the Staphylococcus aureus biofilm formationby 92 and 54%, respectively. However, at the same concentration Mn(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 μg/mL. These results suggest that the metal complex [Mn(H2O)6]0.5[Mn(SMX)3] is agood candidate for the development of new antimicrobial agent acting in part asbactericidal but mainly as antipathogenic agent.