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Percorrer por autor "Lagoa, Ricardo"

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  • The growth curve method to rapidly derive the antibacterial potential of polyoxovanadates
    Publication . Marques-da-Silva, Dorinda; Mal, Sib Sankar; Aureliano, Manuel; Lagoa, Ricardo
    In previous studies (Marques-da-Silva et al., 2019), we measured the minimum inhibitory concentrations (MICs) of three polyoxovanadates, namely V10, MnV11, and MnV13, against Escherichia coli. MICs were obtained following the standard method, which requires a 16–20 h culture and might neglect the effects of the compounds’ metabolism during incubation. In this work, we studied the action of those compounds against Enterococcus faecalis by monitoring the bacterial growth kinetics, and we observed that the inhibition was evident from the beginning of the exponential phase. Notably, data collected from just a 7 h culture was enough to identify the compounds with stronger antibacterial activity according to standard MICs.
    2022-07-10Documento de conferência Acesso aberto Ver mais
  • Polyoxovanadate inhibition of Escherichia coli growth shows a reverse correlation with Ca2+-ATPase inhibition
    Publication . Marques-da-Silva, Dorinda; Fraqueza, Gil; Lagoa, Ricardo; Vannathan, Anjana Anandan; Mal, Sib Sankar; Aureliano, Manuel
    Recently, a global analysis of the structure-activity-relationship of a series of polyoxometalates (POMs) revealed that the most active POMs were ascribed to be polyoxovanadates (POVs), especially decavanadate (V-10), which was very active against certain bacteria (Bijelic et al., Chem. Commun., 2018). The present study explores this observation and compares the effects of three POVs namely MnV11, MnV13 and V-10 against Escherichia coli growth. It was observed that MnV11 presents the lowest growth inhibition (GI(50)) value for Escherichia coli followed by the MnV13 compound, being about 2 times lower than that of V-10 respectively, the values obtained were 0.21, 0.27 and 0.58 mM. All three compounds were more effective than vanadate alone (GI(50) = 1.1 mM) and also than decaniobate, Nb-10 (GI(50) > 10 mM), an isostructural POM of V-10. However, the POVs exhibiting the highest antibacterial activity (MnV11) were shown to have the lowest Ca2+-ATPase inhibitor capacity (IC50 = 58 mM) whereas decavanadate, which was also very active against this membranar ATPase (IC50 = 15 mM), was less active against bacterial growth, suggesting that POV inhibition of ion pumps might not be associated with the inhibition of Escherichia coli growth.
    2019-12Artigo científico Acesso restrito Ver mais