AUTHOR=Gumerova Nadiia I. , Al-Sayed Emir , Krivosudský Lukáš , Čipčić-Paljetak Hana , Verbanac Donatella , Rompel Annette 

TITLE=Antibacterial Activity of Polyoxometalates Against Moraxella catarrhalis

JOURNAL=Frontiers in Chemistry

VOLUME=Volume 6 - 2018

YEAR=2018

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2018.00336

DOI=10.3389/fchem.2018.00336

ISSN=2296-2646

ABSTRACT=The antibacterial activity of 29 different polyoxometalates (POMs) against Moraxella catarrhalis was investigated by determination of the minimum inhibitory concentration (MIC). The Preyssler type polyoxotungstate (POT) [NaP5W30O110]14‒ demonstrates the highest activity against M. catarrhalis (MIC = 1 µg/ml) among all tested POMs. Moreover, we show that the Dawson type based anions, [P2W18O62]6‒, [(P2O7)Mo18O54]4‒, [As2Mo18O62]6‒, [H3P2W15V3O62]6‒ and [AsW18O60]7‒ are selective on M. catarrhalis (MIC range of 2–8 µg/ml). Among the six tested Keggin type based POTs ([PW12O40]3‒, [H2PCoW11O40]5‒, [H2CoTiW11O40]6‒, [SiW10O36]8‒, [SbW9O33]9‒, [AsW9O33]9‒), only the mono-substituted [H2CoTiW11O40]6‒ showed MIC value comparable to those of the Dawson type group. Polyoxovanadates (POVs) and Anderson type POMs were inactive against M. catarrhalis within the tested concentration range (1‒256 µg/ml). Four Dawson type POMs [P2W18O62]6‒, [(P2O7)Mo18O54]4‒, [As2Mo18O62]6‒, [H3P2W15V3O62]6‒ and the Preyssler POT [NaP5W30O110]14‒ showed promising antibacterial activity against M. catarrhalis (MICs < 8 µg/ml) and were therefore tested against three additional bacteria, namely S. aureus, E. faecalis and E. coli. The most potent antibacterial agent was [NaP5W30O110]14‒, exhibiting the lowest MIC values of 16 µg/ml against S. aureus and 8 µg/ml against E. faecalis. The three most active compounds ([NaP5W30O110]14‒, [P2W18O62]6‒ and [H3P2W15V3O62]6‒) show bacteriostatic effects in killing kinetics study against M. catarrhalis. 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.