Antibacterial activities of polythionates enhanced by carbonates

Abstract

Inorganic antibiotics, with low cost, low occurrence of antibacterial resistance, and long-term effects, have attracted great research interest and have been widely used in many fields. However, few investigations have focused on the antibacterial properties of polythionates due to their synthetic difficulty and commercial unavailability. In this work, the antibacterial properties of polythionates, prepared through a new and facile fabrication method, were measured by minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and cup diffusion methods. Moreover, we have proven for the first time that application of polythionates with different bases (carbonate, urea) exhibits enhanced antibacterial activity compared to application of pure polythionates. The increase in antibacterial activity is related to the formation of active sulfur species from the decomposition of polythionates that is promoted by the increase in pH. The MIC of potassium hexathionate against Gram-positive S. aureus and Gram-negative P. aeruginosa, enhanced by adding potassium carbonate, was 7.81 μg mL −1 and 0.98 μg mL −1 , respectively. Therefore, the mixture of polythionate and carbonate is promising as a cheap and sustained antibacterial candidate.Med. Chem. Commun. This journal is

From Elemental Sulfur to Hydrogen Sulfide in Agricultural Soils and Plants

“…In Figure 2, the oxidation activity from S 0 to SO 4 2− is presented on the right side, and shows the Kelly–Trudinger pathway with the production of polythionates such as S 4 O 6 2− and S 3 O 6 2− (as well as S 2 O 3 2− and SO 3 2− ), which serve as a source of reducing potential and possibly act as inducers of stress tolerance in plants, perhaps by containing a single sulfane sulfur not associated with oxygen [16]. In this regard, Li et al [43] described polythionates as agents with antibiotic action, the efficacy of which is variable according to the pH. Additionally, the abiotic oxidation of S 2− in the presence of S 0 produces polysulfides [44], which have been described as agents associated with stress tolerance in animal cells [45].…”