Antibacterial Activity of Polyoxometalates Against .

The antibacterial activity of 29 different polyoxometalates (POMs) against was investigated by determination of the minimum inhibitory concentration (MIC). The Preyssler type polyoxotungstate (POT) [NaPWO] demonstrates the highest activity against (MIC = 1 μg/ml) among all tested POMs. Moreover, we show that the Dawson type based anions, [PWO], [(PO)MoO], [AsMoO], [HPWVO], and [AsWO] are selective on (MIC range of 2-8 μg/ml). Among the six tested Keggin type based POTs ([PWO], [HPCoWO], [HCoTiWO], [SiWO], [SbWO], [AsWO]), only the mono-substituted [HCoTiWO] showed MIC value comparable to those of the Dawson type group. Polyoxovanadates (POVs) and Anderson type POMs were inactive against within the tested concentration range (1-256 μg/ml). Four Dawson type POMs [PWO], [(PO)MoO], [AsMoO], [HPWVO] and the Preyssler POT [NaPWO] showed promising antibacterial activity against (MICs < 8 μg/ml) and were therefore tested against three additional bacteria, namely , and . The most potent antibacterial agent was [NaPWO], exhibiting the lowest MIC values of 16 μg/ml against and 8 μg/ml against . The three most active compounds ([NaPWO], [PWO], and [HPWVO]) show bacteriostatic effects in killing kinetics study against . We demonstrate, that POM activity is mainly depending on composition, shape, and size, but in the case of medium-size POTs (charge is more than -12 and number of addenda atoms is not being higher than 22) its activity correlates with the total net charge.