Browsing by Subject "Antibacterial"

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  • Benetto Tiz, Davide; Skok, Žiga; Durcik, Martina; Tomašič, Tihomir; Peterlin Mašič, Lucija; Ilaš, Janez; Draskovits, Gábor; Révész, Tamás; Nyerges, Ákos; Pál, Csaba; Cruz, Cristina D.; Tammela, Päivi Sirpa Marjaana; Žigon, Dušan; Kikelj, Danijel; Zidar, Nace (2019)
    ATP competitive inhibitors of DNA gyrase and topoisomerase IV have great therapeutic potential, but none of the described synthetic compounds has so far reached the market. To optimise the activities and physicochemical properties of our previously reported N-phenylpyrrolamide inhibitors, we have synthesized an improved, chemically variegated selection of compounds and evaluated them against DNA gyrase and topoisomerase IV enzymes, and against selected Gram-positive and Gram-negative bacteria. The most potent compound displayed IC50 values of 6.9 nM against Escherichia coli DNA gyrase and 960 nM against Staphylococcus aureus topoisomerase IV. Several compounds displayed minimum inhibitory concentrations (MICs) against Gram-positive strains in the 1-50 mu M range, one of which inhibited the growth of Enterococcus faecalis, Enterococcus faecium, S. aureus and Streptococcus pyogenes with MIC values of 1.56 mu M, 1.56 mu M, 0.78 mu M and 0.72 mu M, respectively. This compound has been investigated further on methicillin-resistant S. aureus (MRSA) and on ciprofloxacin non-susceptible and extremely drug resistant strain of S. aureus (MRSA VISA). It exhibited the MIC value of 2.5 mu M on both strains, and MIC value of 32 mu M against MRSA in the presence of inactivated human blood serum. Further studies are needed to confirm its mode of action. (C) 2019 Elsevier Masson SAS. All rights reserved.
  • Lindfors, Nina; Geurts, Jan; Drago, Lorenzo; Arts, J. J.; Juutilainen, Vesa; Hyvönen, Pekka; Suda, Arnold J.; Domenico, Aloj; Artiaco, Stefano; Alizadeh, Chingiz; Brychcy, Adrian; Bialecki, Jertzy; Romano, Carlo L. (Springer International Publishing AG, 2017)
    Advances in Experimental Medicine and Biology
    Osteomyelitis is an infectious process in bone that occasionally leads to bone destruction. Traditionally, the surgical treatment procedure is performed in combination with systemic and local antibiotics as a two-stage procedure that uses autograft or allograft bone for filling of the cavitary defect. Bioactive glass (BAG-S53P4) is a bone substitute with proven antibacterial and bone bonding properties. One hundred and sixteen patients who had verified chronic osteomyelitis was treated using BAG-S53P4 as part of the treatment. Most of the patients had previously undergone numerous procedures, sometimes for decades. A register of patient data obtained from 11 centers from Finland, Italy, the Netherlands, Germany, Azerbaijan and Poland was set-up and continuously maintained at Helsinki University Central Hospital. The location of the osteomyelitis was mainly in the tibia followed by the femur and then the calcaneus. The median age of the patients was 48 years (15-87). The patients were either treated according to a one-stage procedure without local antibiotics (85 %) or by a two-stage procedure using antibiotic beads in the first procedure (15 %). The minimum follow-up was 1 year (12-95 months, median 31). The cure rate was 104/116, the total success rate 90 % and most of the patients showed a rapid recovery. The study shows that (BAG-S53P4) can be used in a one-stage procedure in treatment of osteomyelitis with excellent results.
  • Kanerva, M.; Puolakka, A.; Takala, T.M.; Elert, A.M.; Mylläri, V.; Jönkkäri, I.; Sarlin, E.; Seitsonen, J.; Ruokolainen, J.; Saris, P.; Vuorinen, J. (2019)
    The antibacterial features of natural pine/spruce rosin are well established, yet the functionality in various thermoplastics has not been surveyed. This work focuses on the processing of industrial grade purified rosin mixed with polyethylene (PE), polypropylene (PP), polylactic acid (PLA), polyamide (PA) and corn starch based biopolymer (CS). Homopolymer masterbatches were extrusion-compounded and melt-spun to form fibres for a wide range of products, such as filters, reinforcements, clothing and medical textiles. Due to the versatile chemical structure of rosin, it was observed compatible with all the selected polymers. In general, the rosin-blended systems were shear-thinning in a molten condition. The doped fibres spun of PE and PP indicated adequate melt-spinning capability and proper mechanical properties in terms of ultimate strength and Young's modulus. The antibacterial response was found dependent on the selected polymer. Especially PE with a 10 wt% rosin content showed significant antibacterial effects against Escherichia coli DH5α and Staphylococcus aureus ATCC 12598 when analysed in the Ringer's solution for 24 h.
  • Kanerva, Mikko; Matrenichev, Vsevolod; Layek, Rama; Takala, Timo M.; Laurikainen, Pekka; Sarlin, Essi; Elert, Anna Maria; Yudin, Vladimir; Seitsonen, Jani; Ruokolainen, Janne; Saris, Per (2020)
    The quantitative difference in the antibacterial response was measured for pine rosin and propolis against Staphylococcus aureus ATCC 12598. The activity was studied for fibrous networks that form entirely bio-based cellulose-acetate (CA) materials. The analysis considers the effects of bacterial input, additive dosage, solvent type, variation in preparation, as well as the effect of storage time. Based on the results, the electrospun network structure is dependent on the solvent and the concentration of rosin and propolis. Both rosin and propolis improved the cellulose acetate solution processability, yet they formed beads at high concentrations. Rosin and propolis created strong antibacterial properties when these material systems were immersed in the liquid for 24 h at room temperature. The response remained visible for a minimum of two months. The electrospun networks of water and DMAc solvent systems with 1 to 5 wt% rosin content were clearly more efficient (i.e., decrease of 4 to 6 logs in colony forming units per mL) than the propolis networks, even after two months. This efficiency is likely due to the high content of abietic acids present in the rosin, which is based on the Fourier transform infrared spectra. The results of the additional analysis and cell cultivation with dermal fibroblast cells indicated an impairing effect on skin tissue by the rosin at a 1 wt% concentration compared to the pure CA fibers.
  • Tomašič, Tihomir; Mirt, Matic; Barančoková, Michaela; Ilaš, Janez; Zidar, Nace; Tammela, Päivi Sirpa Marjaana; Kikelj, Danijel (2017)
    Development of novel DNA gyrase B inhibitors is an important field of antibacterial drug discovery whose aim is to introduce a more effective representative of this mechanistic class into the clinic. In the present study, two new series of Escherichia coli DNA gyrase inhibitors bearing the 4,5-dibromopyrrolamide moiety have been designed and synthesized. 4,5,6,7-Tetrahydrobenzo[1,2-d] thiazole-2,6-diamine derivatives inhibited E. coli DNA gyrase in the submicromolar to low micromolar range (IC50 values between 0.891 and 10.4 mu M). Their "ring-opened" analogues, based on the 2-(2-aminothiazol-4-yl) acetic acid scaffold, displayed weaker DNA gyrase inhibition with IC50 values between 15.9 and 169 mu M. Molecular docking experiments were conducted to study the binding modes of inhibitors. (C) 2016 Elsevier Ltd. All rights reserved.
  • Durcik, Martina; Lovison, Denise; Skok, Žiga; Durante Cruz, Cristina; Tammela, Päivi; Tomašič, Tihomir; Benetto Tiz, Davide; Draskovits, Gábor; Nyerges, Ákos; Pál, Csaba; Ilaš, Janez; Peterlin Mašič, Lucija; Kikelj, Danijel; Zidar, Nace (2018)
    The ATP binding site located on the subunit B of DNA gyrase is an attractive target for the development of new antibacterial agents. In recent decades, several small-molecule inhibitor classes have been discovered but none has so far reached the market. We present here the discovery of a promising new series of N-phenylpyrrolamides with low nanomolar IC50 values against DNA gyrase, and submicromolar IC50 values against topoisomerase IV from Escherichia coil and Staphylococcus aureus. The most potent compound in the series has an IC50 value of 13 nM against E. coil gyrase. Minimum inhibitory concentrations (MICs) against Gram-positive bacteria are in the low micromolar range. The oxadiazolone derivative with an IC50 value of 85 nM against E. coli DNA gyrase displays the most potent antibacterial activity, with MIC values of 1.56 mu M against Enterococcus faecalis, and 3.13 mu M against wild type S. aureus, methicillinresistant S. aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). The activity against wild type E. coli in the presence of efflux pump inhibitor phenylalanine-arginine beta-naphthylamide (PA beta N) is 4.6 mu M. (C) 2018 Elsevier Masson SAS. All rights reserved.
  • Dou, Jinze; Rissanen, Marja; Ilina, Polina; Mäkkylä, Heidi; Tammela, Päivi; Haslinger, Simone; Vuorinen, Tapani (2021)
    The development of a mild and green method for separating natural fiber bundles from willow bark is an essential step in exploring and preserving their natural functions. The isolation of well-oriented fiber bundles from the bark of a fast-growing willow hybrid solely using sodium bicarbonate under mild conditions was successfully demonstrated. Additionally, Lyocell fibers were mixed with an equal amount of the willow bark fiber bundles and proved their ability to convert into spun yarns, which provided excellent protection for ultraviolet radiation (UPF > 140). Moreover, these yarns demonstrated strong antibacterial activity (A > 8) against the Gram-positive pathogen Staphylococcus aureus, resulting in complete eradication of viable bacteria after 24 -h incubation with the material. A laundering treatment had no effect on the UV protection or the antibacterial performance. Utilizing these inherent properties from natural fibers for technical textile applications is very promising.
  • Amirsadeghi, Armin; Jafari, Arman; Hashemi, Seyyedeh-Sara; Kazemi, Aboozar; Ghasemi, Younes; Derakhshanfar, Amin; Shahbazi, Mohammad-Ali; Niknezhad, Seyyed Vahid (2021)
    Wound infection is considered a significant challenge in skin injuries. Sprayable antibacterial wound dressings are interesting alternatives to their traditional counterparts because of their facile preparation, ease-of-use, and the possibility of topical delivery of antibacterial materials. Herein, novel sprayable antibacterial dressings are formulated and reported. The dressings were developed by in-situ formation of Ag-nanoparticles (Ag-NPs) using Persian gum (PG) as a carbohydrate polymer. Several tests were conducted to investigate the effect of polymer concentration on the sprayablity, biocompatibility, and antibacterial activity of the dressings (PG/Ag-NPs). Results showed that formulations up to 2 wt.% PG/Ag-NPs could be sprayed properly and form intact films. Antibacterial evaluations also showed biocidal activity of 1% PG/Ag-NPs against Pseudomonas aeruginosa and Staphylococcus aureus. Cytotoxicity and in vivo full-thickness wound healing evaluation confirmed that 1% PG/ Ag-NPs spray was safe and improved wound healing process. All the results confirmed the high potential of formulated sprayable dressings for wound repair.
  • Salih, E.Y.A.; Kanninen, M.; Sipi, M.; Luukkanen, O.; Hiltunen, R.; Vuorela, H.; Julkunen-Tiitto, R.; Fyhrqvist, P. (2017)
    Terminalia laxiflora, Terminalia brownii and Anogeissus leiocarpus are used as decoctions, macerations, infusions and fumigations in East and West African traditional medicine for treatment of infectious diseases and their symptoms. Using this ethnopharmacological information as a guideline for our research and owing to the fact that these species have not been subjected to in depth antibacterial and phytochemical studies, thirty-nine extracts of various polarities of the stem bark, stem wood and roots were studied for growth inhibitory effects against the human pathogenic bacteria Staphylococcus epidermidis, Staphylococcus aureus, Micrococcus luteus and Pseudomonas aeruginosa. Our results indicate that the studied species contain antibacterial compounds of a wide range of polarities. All polar root extracts of T. laxiflora and various polar extracts of T. brownii roots, including hot water decoctions, gave broad-spectrum antibacterial effects and low MIC values of 39 mu g/ml. The main ellagitannins in an ethyl acetate extract of the root of T. laxiflora were found to be corilagin and its derivative and punicalagin. A methanol extract of the roots of T. brownii contained methyl-(S)-flavogallonate and its derivative as the main identified ellagitannins. Moreover, both Terminalia species were found to contain ellagic acid xylopyranoside and methyl ellagic acid xyloside and pure ellagic acid was present in T. brownii. Pure punicalagin did not give as low MIC as an ethyl acetate extract of the roots of T. laxiflora, containing punicalagin as one of its main compounds, although this ellagitannin totally inhibited the growth of S. aureus at 125 mu g/ml and P. aeruginosa at 500 mu g/ml. Similarly, pure ellagic and gallic acid gave higher MIC values than the methanolic root extract of T. brownii against S. aureus and P. aeruginosa. Moreover, a Sephadex LH-20 fraction of the methanolic extract of the roots of T. brownii, enrichedwithmethyl-(S)-flavogallonate and its isomer, gave higher MIC values than the crude methanolic extract. These results suggest that the polyphenols in the extracts might act synergistically with each other. A methanolic soxhlet extract of the roots of A. leiocarpus, containing ampelopsin, aromadendrin, taxifolin, pinosylvin and 4'-methylpinosylvin gave a low MIC value of 39 mu g/ml against all bacterial strains used in this investigation. Our results demonstrate that the roots, stem bark and stem wood of T. brownii, T. laxiflora and A. leiocarpus are rich sources of (new) antimicrobial compounds and justify the uses of these plants for treatment of infections in African traditional medicine.
  • Figueiredo, Joana; Serrano, João L.; Cavalheiro, Eunice; Keurulainen, Leena; Yli-Kauhaluoma, Jari Tapani; Moreira, Vânia M.; Ferreira, Susana; Domingues, Fernanda C.; Silvestre, Samuel; Almeida, Paulo (2018)
    Barbituric and thiobarbituric acid derivatives have become progressively attractive to medicinal chemists due to their wide range of biological activities. Herein, different series of 1,3,5-trisubstituted barbiturates and thiobarbiturates were prepared in moderate to excellent yields and their activity as xanthine oxidase inhibitors, antioxidants, antibacterial agents and as anti-proliferative compounds was evaluated in vitro. Interesting bioactive barbiturates were found namely, 1,3-dimethyl-5-[1-(2-phenylhydrazinyl)ethylidene]pyrimidine-2,4,6(1H,3H,5H)-trione (6c) and 1,3-dimethyl-5-[1-[2-(4-nitrophenyl)hydrazinyl]ethylidene]pyrimidine-2,4,6(1H,3H,5H)-trione (6e), which showed concomitant xanthine oxidase inhibitory effect (IC50 values of 24.3 and 27.9 mu M, respectively), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (IC50 values of 18.8 and 23.8 mu M, respectively). In addition, 5-[1-(2-phenylhydrazinyl)ethylidene]pyrimidine-2,4,6(1H,3H,5H)-trione (6d) also revealed DPPH radical scavenger effect, with an IC50 value of 20.4 mu M. Moreover, relevant cytotoxicity against MCF-7 cells (IC50 = 13.3 mu M) was observed with 5-[[(2-chloro-4-nitrophenyl)amino]methylene]-2-thioxodihydropyrimidine-4,6(1H,5H)-dione (7d). Finally, different 5-hydrazinylethylidenepyrimidines revealed antibacterial activity against Acinetobacter baumannii (MIC values between 12.5 and 25.0 mu M) which paves the way for developing new treatments for infections caused by this Gram-negative coccobacillus bacterium, known to be an opportunistic pathogen in humans with high relevance in multidrug-resistant nosocomial infections. The most promising bioactive barbiturates were studied in silico with emphasis on compliance with the Lipinski's rule of five as well as several pharmacokinetics and toxicity parameters. (C) 2017 Elsevier Masson SAS. All rights reserved.