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Poly(ethylene terephthalate) (PET) is widely used material in the healthcare due to its mechanical properties including resistance to chemicals and abrasion. However, it is susceptible to bacterial attachment and contamination. This study addresses some newly designed model compounds of PET with antimicrobial properties that could potentially be incorporated into PET materials. All compounds were synthesized for the first time by labeling an integral part of PET with chromophores in the form of esters of cinnamic and ferulic acids. After complete structural characterization, the effect of new compounds on microbial growth and communication (quorum sensing, QS) was analyzed and further investigated using molecular docking. The obtained results indicate that the introduction of chromophores that have one part of cinnamic acid enriched with a methoxy functional group in them acts as QS modulators. Moreover, compounds exhibited dose-dependent selectivity toward QS signaling pathways and the highest tested concentration of compounds showed Pseudomonas Quinolone Signal (PQS) inhibitory activity suggesting that these compounds have a potential effect on pyocyanin production. Docking studies demonstrated that compounds hold binding power to all four QS protein targets (LuxP, periplasmatic protein that binds AI-2 inducer and forms a complex able to transduce the autoinducer signal, RhIR protein that is a key QS transcriptional regulator that activates the genes involved in the synthesis of rhamnolipids and pyocyanin, AbaI protein that has a role in QS signal transduction, and LasR protein which is a key QS transcriptional regulator that activates transcription of genes coding for some virulence-associated traits) while the highest binding strength is observed with compounds 2 and 6 containing single cinnamic acid fragment, suggesting their further biomedical application.

Polyurethanes (PUs) are an exceedingly heterogeneous group of plastic polymers, widely used in a variety of industries from construction to medical implants. In the past decades, we have witnessed the accumulation of PU waste and its detrimental environmental impacts. PUs have been identified as one of the most toxic polymers leaching hazardous compounds derived both from the polymer itself and the additives used in production. Further environmental impact assessment, identification and characterization of substances derived from PU materials and establishing efficient degradation strategies are crucial. Thus, a selection of eight synthetic model compounds which represent partial PU hydrolysis products were synthesized and characterized both in terms of toxicity and suitability to be used as substrates for the identification of novel biocatalysts for PU biodegradation. Overall, the compounds exhibited low in vitro cytotoxicity against a healthy human fibroblast cell line and virtually no toxic effect on the nematode Caenorhabditis elegans up to 500 µg mL−1, and two of the substrates showed moderate aquatic ecotoxicity with EC50 values 53 µg mL−1 and 45 µg mL−1, respectively, on Aliivibrio fischeri. The compounds were successfully applied to study the mechanism of ester and urethane bond cleaving preference of known plastic-degrading enzymes and were used to single out a novel PU-degrading biocatalyst, Amycolatopsis mediterranei ISP5501, among 220 microbial strains. A. mediterranei ISP5501 can also degrade commercially available polyether and polyester PU materials, reducing the average molecular number of the polymer up to 13.5%. This study uncovered a biocatalyst capable of degrading different types of PUs and identified potential enzymes responsible as a key step in developing biotechnological process for PU waste treatment options.

Polyurethanes (PUs) are an exceedingly heterogeneous group of plastic polymers, widely used in a variety of industries from construction to medical implants. In the past decades, we have witnessed the accumulation of PU waste and its detrimental environmental impacts. PUs have been identified as one of the most toxic polymers leaching hazardous compounds derived both from the polymer itself and the additives used in production. Further environmental impact assessment, identification and characterization of substances derived from PU materials and establishing efficient degradation strategies are crucial. Thus, a selection of eight synthetic model compounds which represent partial PU hydrolysis products were synthesized and characterized both in terms of toxicity and suitability to be used as substrates for the identification of novel biocatalysts for PU biodegradation. Overall, the compounds exhibited low in vitro cytotoxicity against a healthy human fibroblast cell line and virtually no toxic effect on the nematode Caenorhabditis elegans up to 500 µg mL−1, and two of the substrates showed moderate aquatic ecotoxicity with EC50 values 53 µg mL−1 and 45 µg mL−1, respectively, on Aliivibrio fischeri. The compounds were successfully applied to study the mechanism of ester and urethane bond cleaving preference of known plastic-degrading enzymes and were used to single out a novel PU-degrading biocatalyst, Amycolatopsis mediterranei ISP5501, among 220 microbial strains. A. mediterranei ISP5501 can also degrade commercially available polyether and polyester PU materials, reducing the average molecular number of the polymer up to 13.5%. This study uncovered a biocatalyst capable of degrading different types of PUs and identified potential enzymes responsible as a key step in developing biotechnological process for PU waste treatment options.

In a search for novel antimicrobial metal-based therapeutic agents, mononuclear gold(III) complexes 1-7 of the general formula [AuCl3(azole)], where azole stands for imidazole (im, 1), 1-isopropylimidazole (ipim, 2), 1-phenylimidazole (phim, 3), clotrimazole (ctz, 4), econazole (ecz, 5), tioconazole (tcz, 6) and voriconazole (vcz, 7) were synthesized, characterized and biologically evaluated. In all complexes, the corresponding azole ligand is monodentately coordinated to the Au(III) via the imidazole or triazole nitrogen atom, while the remaining coordination sites are occupied by chloride anions leading to the square-planar arrangement. In vitro antimicrobial assays showed that the complexation of inactive azoles, imidazole, 1-isopropylimidazole and 1-phenylimidazole, to the Au(III) ion led to complexes 1-3, respectively, with moderate activity against the investigated strains and low cytotoxicity on the human normal lung fibroblast cell line (MRC-5). Moreover, gold(III) complexes 4-7 with clinically used antifungal agents clotrimazole, econazole, tioconazole and voriconazole, respectively, have, in most cases, enhanced antimicrobial effectiveness relative to the corresponding azoles, with the best improvement achieved after complexation of tioconazole (6) and voriconazole (7). The complexes 4-7 and the corresponding antifungal azoles inhibited the growth of dermatophyte Microsporum canis at 50 and 25 mu g mL(-1). Gold(III) complexes 1-3 significantly reduced the amount of ergosterol in the cell membrane of Candida albicans at the subinhibitory concentration of 0.5 x MIC (minimal inhibitory concentration), while the corresponding imidazole ligands did not significantly affect the ergosterol content, indicating that the mechanism of action of the gold(III)-azole complexes is associated with inhibition of ergosterol biosynthesis. Finally, complexes 5 and 6 significantly reduced the production of pyocyanin, a virulence factor in Pseudomonas aeruginosa controlled by q

Prodigiosins (prodiginines) are a class of bacterial secondary metabolites with remarkable biological activities and color. In this study, optimized production, purification, and characterization of prodigiosin (PG) from easily accessible Serratia marcescens ATCC 27117 strain has been achieved to levels of 14 mg/L of culture within 24 h. Furthermore, environmentally friendly bromination of produced PG was used to afford both novel mono- and dibrominated derivatives of PG. PG and its Br derivatives showed anticancer potential with IC50 values range 0.62-17.00 mu g/mL for all tested cancer cell lines and induction of apoptosis but low selectivity against healthy cell lines. All compounds did not affect Caenorhabditis elegans at concentrations up to 50 mu g/mL. However, an improved toxicity profile of Br derivatives in comparison to parent PG was observed in vivo using zebrafish (Danio rerio) model system, when 10 mu g/mL applied at 6 h post fertilization caused death rate of 100%, 30% and 0% by PG, PG-Br, and PG-Br-2,Br- respectively, which is a significant finding for further structural optimizations of bacterial prodigiosins. The drug-likeness of PG and its Br derivatives was examined, and the novel Br derivatives obey the Lipinski's "rule of five", with an exemption of being more lipophilic than PG, which still makes them good targets for further structural optimization.

To investigate how modification in the structure of 1,3-propanediamine chain of 1,3-pdta (1,3-propanediamine-N,N,N′,N′-tetraacetate) ligand affects the structural and biological properties of the corresponding metal complexes, two new octahedral complexes, [Co(H2O)5Co(2,2-diMe-1,3-pdta)]·H2O (1) and [Mg(H2O)5Mg(2,2-diMe-1,3-pdta)]·1.5H2O (2) (2,2-diMe-1,3-pdta = 2,2-dimethyl-1,3-propanediamine-N,N,N′,N′-tetraacetate), were synthesized and characterized by IR spectroscopy and single-crystal X-ray diffraction analysis. Additionally, UV-Vis and NMR spectroscopic methods were applied for the characterization of 1 and 2, respectively. Crystallographic data indicate that these complexes contain 2,2-diMe-1,3-pdta coordinated to the metal ion through 2 N and 4 O atoms forming [M(H2O)5M′(2,2-diMe-1,3-pdta)] complex unit (M, M′ = Co(II), Co(II) (1) and M, M′ = Mg(II), Mg(II) (2)), which is composed of [M′(2,2-diMe-1,3-pdta)]2− and [M(H2O)5O]2+ octahedra bridged by one of the axial carboxylate groups. The antimicrobial activities of 1 and 2 were evaluated against different bacteria and Candida spp., while their cytotoxic effect was tested on the normal human lung fibroblasts (MRC-5). The ability of 1 and 2 to inhibit formation of C. glabrata biofilms was also assessed. The obtained structural parameters and biological properties of the two complexes were compared to Co(II) and Mg(II) complexes with 1,3-pdta ligand.

Three new silver(I) complexes [Ag(NO3)(tia)(H2O)](n) (Ag1), [Ag(CF3SO3)(1,8-naph)](n) (Ag2) and [Ag-2(1,8-naph)(2)(H2O)(1.2)](PF6)(2) (Ag3), where tia is thianthrene and 1,8-naph is 1,8-naphthyridine, were synthesized and structurally characterized by different spectroscopic and electrochemical methods and their crystal structures were determined by single-crystal X-ray diffraction analysis. Their antimicrobial potential was evaluated against four bacterial and three Candida species, and the obtained results revealed that these complexes showed significant activity toward the Gram-positive Staphylococcus aureus, Gram-negative Pseudomonas aeruginosa and the investigated Candida species with minimal inhibitory concentration (MIC) values in the range 1.56-7.81 mu g/mL. On the other hand, tia and 1,8-naph ligands were not active against the investigated strains, suggesting that their complexation with Ag(I) ion results in the formation of antimicrobial compounds. Moreover, low toxicity of the complexes was detected by in vivo model Caenorhabditis elegans. The interaction of the complexes with calf thymus DNA (ct-DNA) and bovine serum albumin (BSA) was studied to evaluate their binding affinity towards these biomolecules for possible insights into the mode of antimicrobial activity. The binding affinity of Ag1-3 to BSA was higher than that for DNA, indicating that proteins could be more favorable binding sites for these complexes in comparison to the nucleic acids.

Sulfonamides represent the oldest synthetic antibacterial agents; however, their central position in controlling bacterial diseases has been seriously damaged by the development of widespread resistance. Herein, we revisited sulfathiazole, a commercial member of antibacterial sulfa drugs, intending to overcome sulfonamide resistance and identify new drug candidates through molecular modifications. We synthesized twelve sulfonamides (SA1-SA12) by replacing the amino group on the phenyl ring with various substituents and introducing a thiophene ring on the core scaffold of sulfathiazole. The obtained compounds and additionally two commercial sulfonamides, sulfathiazole and sulfadiazine, were extensively screened for their antimicrobial activities. The results indicated that new sulfonamides, unlike traditional ones, were selectively effective against various Staphylococcus aureus strains. Introducing a bulky lipophilic substituent at the para position of the phenyl ring significantly increased the antibacterial activities of the compounds against Staphylococcus aureus. The compounds demonstrating favourable selectivity indices were further evaluated for their membrane potential perturbation and DNA interaction properties. The obtained data showed that these are not supporting mechanisms for the antibacterial activities of the modified sulfathiazole derivatives. In order to rationalize the activity of the three most active compounds, SA7, SA11 and SA12, against S. aureus ATCC 25923, their binding hypotheses within the catalytic site of Staphylococcus aureus dihydropteroate synthase, the validated target enzyme of sulfonamides, were generated via molecular docking and further dissected using molecular dynamics simulations and dynamic 3D pharmacophores (dynophores).

Copper(II) and zinc(II) complexes with clinically used antifungal drug fluconazole (fcz), {[CuCl2(fcz)(2)](.)5H(2)O}(n), 1, and {[ZnCl2(fcz)(2)]Greek ano teleia2C(2)H(5)OH}(n), 2, were prepared and characterized by spectroscopic and crystallographic methods. The polymeric structure of the complexes comprises four fluconazole molecules monodentately coordinated via the triazole nitrogen and two chlorido ligands. With respect to fluconazole, complex 2 showed significantly higher antifungal activity against Candida krusei and Candida parapsilosis. All tested compounds reduced the total amount of ergosterol at subinhibitory concentrations, indicating that the mode of activity of fluconazole was retained within the complexes, which was corroborated via molecular docking with cytochrome P450 sterol 14 alpha-demethylase (CYP51) as a target. Electrostatic, steric and internal energy interactions between the complexes and enzyme showed that 2 has higher binding potency to this target. Both complexes showed strong inhibition of C. albicans filamentation and biofilm formation at subinhibitory concentrations, with 2 being able to reduce the adherence of C. albicans to A549 cells in vitro. Complex 2 was able to reduce pyocyanin production in Pseudomonas aeruginosa between 10% and 25% and to inhibit its biofilm formation by 20% in comparison to the untreated control. These results suggest that complex 2 may be further examined in the mixed Candida-P. aeruginosa infections.

New silver(I) complex with thianthrene (tia), [Ag(NO3)(tia)(H2O)]n, was synthesized by the reaction of AgNO3 with an equimolar amount of tia in ethanol/dichloromethane (v/v 1:1) at room temperature, and characterized by NMR, IR and UV-Vis spectroscopy and single-crystal X-ray diffraction analysis. The antimicrobial activity of the synthesized complex was evaluated against the broad panel of Gram-positive and Gram-negative bacteria and Candida spp. This complex showed significant activity toward important human pathogens Gram-positive Staphylococcus aureus and Candida parapsilosis with minimal inhibitory concentrations (MICs) being 3.91 µg/mL. The interaction of [Ag(NO3)(tia)(H2O)]n with calf thymus DNA (ct-DNA) and bovine serum albumin (BSA) was studied to evaluate the binding affinity towards these biomolecules for possible insights on the mode of antimicrobial activity. The binding affinity of the investigated complex to BSA is higher than that for DNA, indicating that proteins could be more favorable binding sites for this complex in comparison to the nucleic acids.

Plastic pollution is now considered one of the largest environmental threats facing humans and animals globally. Development of bioplastic materials may offer part of the solution as bioplastics include both nondegradable and biodegradable materials with both being important for sustainability. Bioplastic materials are currently being designed to encompass minimal carbon footprint, high recycling value and complete biodegradability. This review examines recent developments and trends in the field of bioplastic materials. A range of the most utilized bioplastic materials is presented (poly(lactic acid) (PLA), polyhydroxyalkanoate (PHA), starch, cellulose, bio-based poly(butylene succinate) (bio-PBS) and bio-polyethylene (bio-PE)) including their production, application and degradation options.

The excited-state heterolysis of acridinol-based derivatives leads to the release of the OH- ion and the formation of the corresponding acridinium cations. To evaluate the parameters that control the reaction barriers, the kinetics of excited-state OH- release from a series of acridinol photobases were studied using transient absorption spectroscopy. The rate constants were obtained in three solvents (methanol, butanol, and isobutanol), and the data were modeled using Marcus theory. The intrinsic reorganization energies obtained from these fits were found to correlate well with the solvent reorganization energies calculated using dielectric continuum model, suggesting that the excited-state OH- release occurs along the solvent reaction coordinate. Furthermore, the ability of acridinol photobases to photoinitiate chemical reactions was demonstrated using the Michael reaction between dimethylmalonate and nitrostyrene.

A library of 18 different compounds was synthesized starting from (R)-3-hydroxyoctanoic acid which is derived from the bacterial polymer polyhydroxyalkanoate (PHA). Ten derivatives, including halo and unsaturated methyl and benzyl esters, were synthesized and characterized for the first time. Given that (R)-3-hydroxyalkanoic acids are known to have biological activity, the new compounds were evaluated for antimicrobial activity and in vitro antiproliferative effect with mammalian cell lines. The presence of the carboxylic group was essential for the antimicrobial activity, with minimal inhibitory concentrations against a panel of bacteria (Gram-positive and Gram-negative) and fungi (Candida albicans and Microsporum gypseum) in the range 2.8-7.0 mM and 0.1-6.3 mM, respectively. 3-Halogenated octanoic acids exhibited the ability to inhibit C. albicans hyphae formation. In addition, (R)-3-hydroxyoctanoic and (E)-oct-2-enoic acids inhibited quorum sensing-regulated pyocyanin production in the opportunistic pathogen Pseudomonas aeruginosa PAO1. Generally, derivatives did not inhibit mammalian cell proliferation even at 3-mM concentrations, while only (E)-oct-2-enoic and 3-oxooctanoic acid had IC50 values of 1.7 and 1.6 mM with the human lung fibroblast cell line.