Fast and efficient galvanostatic conversion of 2,4-diarylfurans into dimeric furan-2(5)-ones is now possible in one pot and good yields at room temperature in sustainable aqueous organic solvent. Recent applications of these highly desired structures demand our attention since they are a versatile alternative to acrylates in polymerization to achieve green materials. The reaction mechanism proposal, supported by density functional theory (DFT) theoretical calculations, involves furanoxy radicals, detected by electron paramagnetic resonance (EPR), as the last intermediate before a homocoupling step that affords butenolides.
View Article and Find Full Text PDFAntibiotic resistance is currently a global health emergency. Metallodrugs, especially metal coordination complexes, comprise a broad variety of candidates to combat antibacterial infections. In this work, we designed a new family of Schiff base zinc(II) complexes with iminopyridine as an organic ligand and different inorganic ligands: chloride, nitrate, and acetate.
View Article and Find Full Text PDFThe development of biofilms on different surfaces continues to be a major public health problem. The antimicrobial resistance and the difficulty of finding drugs capable of combating these established biofilms generates the urgent need to find compounds that prevent cells from settling and establishing of these complex communities of microorganisms. Zwitterionic modification of nanomaterials allows the formation of a hydration layer, and this highly hydrophilic surface provides antifouling properties as well as a good biocompatibility by preventing non-specific interactions.
View Article and Find Full Text PDFAerosolized anthrax () spores are of extreme health concern and can remain airborne for hours and contaminate all kinds of surfaces, constituting reservoirs from which resuspension is easily produced. The assessment of decontamination techniques must therefore consider both air and surfaces. In the present study, several kinds of disinfecting fogs were experimentally tested against spores, which served as a surrogate for , both as aerosols released into the air and spread on porous and non-porous surfaces with different positions and orientations.
View Article and Find Full Text PDFIn the last decade, has become an important emerging opportunistic pathogen not only because of the increase in nosocomial infections frequency but also because of its ability to form biofilms and its innate resistance to commercial antifungals. These characteristics make this pathogen a major problem in hospital settings, including problems regarding equipment, and in immunosuppressed patients, who are at high risk for candidemia. Therefore, there is an urgent need for the development of and search for new antifungal drugs.
View Article and Find Full Text PDFis a human pathogen of significant clinical relevance. This pathogen is resistant to different drugs, and most clinical antifungals are not effective against the prevention and treatment of infections. As with other microorganisms, it can produce biofilms that serve as a barrier against antifungal agents and other substances, contributing to infection in humans and environmental tolerance of this microorganism.
View Article and Find Full Text PDFBiofilm formation is a critical health concern, involved in most human bacterial infections. Combatting this mechanism, which increases resistance to traditional antibiotics and host immune defences, requires novel therapeutic approaches. The remarkable biocide activity and the monodispersity of carbosilane metallodendrimers make them excellent platforms to evaluate the impact of different structural parameters on the biological activity.
View Article and Find Full Text PDFSpherical dendrimers and dendrons containing silver(I) -heterocyclic carbenes (Ag(I)-NHC) and additionally bow-tie metal-free dendritic systems were synthesized in a simple and straightforward synthetic procedure and subsequently characterized. The antibacterial activity was evaluated, and in parallel, a comparative study with the cationic analogue precursors was performed to explore the effect of silver ions in the dendritic structure. Other parameters, such as topology, generation, and hydrophobicity, of the imidazole substituents were also studied.
View Article and Find Full Text PDFspp. are one of the most common fungal pathogens. Biofilms formed by offer resistance mechanisms against most antifungal agents.
View Article and Find Full Text PDFCationic carbosilane dendrimers are branched molecules with antimicrobial properties. Their activity has been tested against , a causative agent of keratitis, a severe ocular disease in humans. trophozoites and cysts were exposed to different noncytotoxic cationic carbosilane dendrimers with proven antiamoebic activity.
View Article and Find Full Text PDFWe characterised 80 Staphylococcus aureus strains isolated from human patients with SSTIs at a rural hospital in Ethiopia. Susceptibility to antibiotic of all strains was tested. The MLST method was used to type and a phylogenetic analysis was conducted employing the sequences of 7 housekeeping genes.
View Article and Find Full Text PDFAntibiotic resistance is currently one of the main threats to public health security. Biofilm formation is a resistance mechanism that is responsible for most human bacterial infections and requires new and effective therapeutic approaches, such as those provided by nanotechnology. In this work, the antibacterial effect of carbosilane metallodendrimers with different metals (copper(II) and ruthenium(II)), ligands (chloride and nitrate) and generations (generation 0, 1 and 2) has been studied using planktonic Gram-positive () and Gram-negative () bacteria.
View Article and Find Full Text PDFA series of novel water-soluble ammonium-terminated carbosilane dendrons containing a ferrocene unit at the focal point were synthesized, in order to combine the unique redox activity of ferrocene and the precisely designed structure of the dendrons with the aim to evaluate them as a new class of potential organometallic-based antibacterial compounds. The synthetic route is based on the initial amination of ferrocenecarboxaldehyde with carbosilane dendrons that contain allyl groups on the surface followed by reduction of the in situ prepared imine product, and the subsequent functionalization of the periphery with terminal amine groups by hydrosilylation reactions. Systems quaternized with HCl are soluble and stable in water or other protic solvents.
View Article and Find Full Text PDFA novel pink-pigmented bacterial strain, UAH-SP71T, was isolated from a saltern located in Santa Pola, Alicante (Spain) and the complete genome sequence was analysed and compared with that of Spiribacter salinus M19-40T, suggesting that the two strains constituted two separate species, with a 77.3% ANI value. In this paper, strain UAH-SP71T was investigated in a taxonomic study using a polyphasic approach.
View Article and Find Full Text PDFDendrimers are repetitively branched molecules with a broad spectrum of applications, mainly for their antimicrobial properties and as nanocarriers for other molecules. Recently, our research group have synthesized and studied their activity against Acanthamoeba sp., causative agent of a severe ocular disease in humans: Acanthamoeba keratitis.
View Article and Find Full Text PDFBackground: Thalassosaline waters produced by the concentration of seawater are widespread and common extreme aquatic habitats. Their salinity varies from that of sea water (ca. 3.
View Article and Find Full Text PDFA new family of amine- and ammonium-terminated hyperbranched polycarbosilanes (PCS) and dendrimers has been synthesized. The functionalization of a polycarbosilane matrix was carried out with peripheral allyl groups by two strategies in the case of PCS: 1) hydrosilylation of allyl amines with PCS containing terminal Si-H bonds, or 2) hydrosilylation of PCS-allyl with an aminosilane. Dendrimers with terminal amine groups were synthesized by hydrosilylation of allydimethylamine.
View Article and Find Full Text PDFA new family of amine- and ammonium-terminated carbosilane dendrimers of the type Gn-[Si(CH2)3N(Et)CH2CH2NMe2]x and Gn-{[Si(CH2)(3)N+R(Et)CH2CH2N+RMe2]x(X-)y} (where n = 1, 2 and 3; R = H, X = Cl; R = Me, X = I) respectively has been synthesized by hydrosilylation of N,N-dimethyl-N'-allyl-N'-ethyl-ethylenediamine, [(CH2=CH-CH2)(Et)N(CH2)2NMe2] with the corresponding hydride-terminated dendrimers and subsequent quaternization with HCl or MeI. Quaternized dendrimers are soluble and stable in water or other protic solvents for long time periods. The antibacterial properties of the quaternary ammonium functionalized dendrimers have been evaluated showing that they act as potent biocides in which the multivalency along with the biopermeability of the carbosilane dendritic skeleton play an important role in the antibactericidal activity of these compounds.
View Article and Find Full Text PDFNovel amine- and ammonium-terminated carbosilane dendrimers of type G(n)-[Si{CH(2)O-(C(6)H(4))-3-NMe(2)}](x) or G(n)-[Si{CH(2)O-(C(6)H(4))-3-NMe(3)(+)I(-)}](x) have been synthesized and characterized up to second generation by phenolysis of (chloromethyl)silyl-terminated dendrimers with 3-dimethylamine phenol and subsequent quaternization with methyl iodide. Quaternized carbosilane dendrimers are stable in protic solvents and can be solubilised in water after the addition of less than 1% of dimethyl sulfoxide. A study of the antimicrobial activity of these cationic dendrimers of first and second generation against both gram-positive and gram-negative bacteria is also described.
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