WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 76Citation - Scopus: 82Multicolor Emitting Carbon Dot-Reinforced Pva Composites as Edible Food Packaging Films and Coatings With Antimicrobial and Uv-Blocking Properties(American Chemical Society, 2022) Alaş, Melis Özge; Doğan, Gamze; Yalçın, Mustafa Serkan; Özdemir, Sadin; Genç, RükanActive food packaging has become attractive because of the possibility to provide a longer shelf-life by loading functional agents into the packages to maintain the quality of food products. Herein, photoluminescent and transparent polyvinyl alcohol (PVA)-based composites embedding multicolor fluorescent carbon dots (CD/PVA) were prepared by the solvent casting method. The prepared CDs emit a strong and stable fluorescence in solution while the CD/PVA composite films were transparent, flexible, and showed UV-blocking activity with a strong fluorescence emission. Blue color-emitting CDs showed the highest UV blockage at UVA (87.04%), UVB (87.04%), and UVC (92.22%) regions while PVA alone absorbed only less than 25% of the light in all UV regions. UV blockage capacity was shown to be decreased by half, in line with the emission color shift from blue to red. Thermal properties of the PVA film were improved by the addition of CDs to the polymer, and in vitro cell viability tests showed that none of the CDs were cytotoxic against the human lung fibroblast healthy cell line (MRC-F cells) when integrated into the PVA. The antimicrobial activity of CD/PVA nanofilms was qualitatively determined. The prepared films exhibited good antimicrobial activity against both Gram-positive and Gram-negative bacteria with mild antioxidant and metal chelating activity, and significant inhibition of biofilm formation with a strong link with emitted color and the concentration of the composites. Green- and red-emitting CD/PVA with the highest antimicrobial activity were then analyzed and compared with the plane PVA employing their effect on the shelf-life of strawberries as a model for perishable foods. Fresh strawberries dip coated with CD/PVA and PVA were monitored over time, and virtual evaluations showed that CDs/PVA film coating resulted in reduced weight and moisture loss and significantly inhibited the fungal growth and spoiling for over 6 days at RT and 12 days at fridge conditions maintaining the visual appearance and natural color of the fruit. The findings in this work indicated the potential of reported CD as non-cytotoxic, UV-blocking antimicrobial additives for the development of edible coatings and packages for their use in the food industry, as well as pharmaceutical and healthcare applications.Article Citation - WoS: 6Citation - Scopus: 6Benzodiazepine Derivatives From Marine-Derived Streptomyces Cacaoi 14cm034(ACG Publications, 2021) Çetinel Aksoy, Semiha; Küçüksolak, Melis; Uzel, Ataç; Bedir, Erdal7-methoxy-8-hydroxy cycloanthranilylproline (2), a new natural product with pyrrolobenzodiazepine (PBD) framework, was isolated from marine-derived actinobacterium Streptomyces cacaoi 14CM034, together with cycloanthranilylproline (1). Structural elucidation of the compounds was based on FTIR, 1D-(H-1 and C-13 NMR), 2D-NMR (COSY, HMBC and NOESY) and HR-MS analyses. Compounds 1 and 2 exhibited notable antimicrobial activity. The presence of PBD derivatives in S. cacaoi was first demonstrated with this study.Article Citation - WoS: 6Antioxidant, Antimicrobial and Cytotoxic Activities of Extracts From Some Selected Mediterranean Shrub Species (maquis)(Biointerface Research Applied Chemistry, 2016) Bayraktar, Oğuz; Altıok, Evren; Yılmazer, Özgür; Rusçuklu, Dane; Büyüköz, MeldaIn this study in vitro antioxidant, antimicrobial and cytotoxic activities of ethanol extracts of some plants from Urla region in Turkey were investigated. Plant material samples of Pistacia lentiscus, Vitex agnus-castus, Cistus creticus and Nerium oleander were collected in October, November and December. The harvesting time significantly affected their antioxidant, antimicrobial and cytotoxic activities of these plant extracts. The highest biological activities in terms of antioxidant, antimicrobial and cytotoxic activities were observed for the leaf extract of C. creticus. The applied doses of leaf extracts of C. creticus, P. lentiscus, and N. oleander resulted in higher Bax and GAPDH expressions than those for control cells. These plant extracts may trigger apoptosis and may be a promising natural source for prostate cancer treatment.Article Citation - WoS: 13Citation - Scopus: 17Characterization of Antimicrobial Activities of Olive Phenolics on Yeasts Using Conventional Methods and Mid-Infrared Spectroscopy(Springer, 2019) Canal, Canan; Özen, Banu; Baysal, Ayşe HandanOlive fruit is very rich in terms of phenolic compounds. Antimicrobial activities of various phenolic compounds against bacteria and fungi are well established; however, their effects on yeasts have not been examined. Aim of this study was to investigate the antimicrobial effects induced by olive phenolic compounds, including tyrosol, hydroxytyrosol, oleuropein, luteolin and apigenin against two yeast species, Aureobasidium pullulans and Saccharomyces cerevisiae. For this purpose, yeasts were treated with various concentrations (12.5-1000ppm) of phenolic compounds and reduction in yeast population was followed with optical density measurements with microplate reader, yeast colony forming units and mid-infrared spectroscopy. All phenolic compounds were effective on both yeasts, especially 200ppm and higher concentrations have significant antimicrobial activity; however, effects of lower levels depend on the type of phenolic compound. According to mid-infrared spectral data, significant changes were observed in 1200-900cm(-1) range corresponding to carbohydrates of yeast structure as a result of exposure to all phenolic compounds except tyrosol. Spectra of tyrosol and luteolin treated yeasts also showed changes in 1750-1500cm(-1) related to amide section and 3600-3000cm(-1) fatty acid region. Since phenolic compounds from olives were effective against yeasts, they could be used in food applications where yeast growth showed problem. In addition, FTIR spectroscopy could be successfully used to monitor and characterize antimicrobial activity of phenolic compounds on yeasts as complementary to conventional microbiological methods.Article Evaluation of Aluminum Stress Induced Antibacterial and Antifungal Activities in Roman Nettle(Parlar Scientific Publications, 2019) Özyiğit, İbrahim İlker; Doğan, İlhan; Yalçın, İbrahim Ertuğrul; Severoğlu, ZekiIn this current work, Roman nettle (Urtica pilulifera L.), a traditional medicinal plant that is very common and widespread species throughout Asia, Europe, and Northern Africa, was used as a model plant to investigate changes in antimicrobial activity following the application of aluminum stress. U pilulifera seedlings were grown in growth-room conditions and 0, 100, and 200 M AlCl3 were applied to the plants together with Hoagland solution (20 ml) for two months. The antimicrobial activities were tested against nine strains of bacteria (Salmonella sp., Staphyllococcus aureus, Escherichia coli, E. coli O157:H7 and Bacillus cereus) and fungus (Penicillum sp., Saccharomyces cerevisiae, Candida tropicans and C. albicans) by using the disc diffusion and agar well methods. The accumulated Al was measured by using ICP-OES in the leaves of studied plant samples. Additionally, a control group (water + 11.31 mg l(-1) Al) was prepared and applied to selected bacteria and fungi in order to understand the reason for obtained antimicrobial activities of Roman nettle is whether because of the compounds isolated from nettle leaves exposed to Al stress, or Al itself accumulated in leaves. The data proved that inhibitory antimicrobial effects were altered in U pilulifera upon the application of Al stress, especially on fungi species.Article Citation - WoS: 96Citation - Scopus: 113Hypericum Perforatum Incorporated Chitosan Films as Potential Bioactive Wound Dressing Material(Elsevier Ltd., 2017) Güneş, Seda; Tıhmınlıoğlu, FundaRecent studies in wound dressing applications offer new therapies and promote wound healing process. The aim of this study was to develop Hypericum perforatum (St John's Wort) oil incorporated chitosan films for wound dressing applications. H. perforatum oil as a potential therapeutic agent was encapsulated in chitosan film to achieve a better wound dressing material. Oil incorporated chitosan films were successfully prepared by solvent casting method in different oil concentrations (0.25–1.5%v/v). Water vapor permeability (WVP), mechanical test, swelling behavior and surface hydrophobicity were performed in order to characterize the prepared films. Antimicrobial test was performed by disc diffusion method and the growth inhibition effects of the films including different amount of H. perforatum oil were investigated on Escherichia coli and Staphylococcus aureus. WVP increased with oil incorporation and the highest value was obtained for 0.25% oil concentration.The highest strain value was obtained in 0.25% oil content films although tensile stress decreased with increasing oil content. H. perforatum oil incorporated films had antimicrobial effect on both microorganisms. Chitosan based films had no cytotoxic effects on NIH3T3fibroblast cells and provided a good surface for cell attachment and proliferation. The results showed that the H. perforatum incorporated chitosan films seems to be a potential and novel biomaterial for wound healing applications.Article Citation - WoS: 14Citation - Scopus: 16Antimicrobial Activity and Chemical Composition Screening of Epilobium Montanum Root(Association of Pharmaceutical Teachers of India, 2017) Canlı, Kerem; Yetgin, Ali; Akata, Ilgaz; Altuner, Ergin MuratMedical herbs have many bioactive component and they are used in microbial treatment since ancient time. The resistance of pathogen to antibiotic is became a critical problem, so novel antimicrobial agent related research is required. Epilobium montanum related antimicrobial research doesn’t exist, therefore root of this medicinal plant investigation was applied against 17 bacteria and 1 fungi by using disk diffusion method. These microbial species include Bacillus, Enterobacter, Enterococcus, Escherichia, Klebsiella, Listeria, Pseudomonas, Salmonella, Staphylococcus and Candida genera. Besides, chemical composition of this sample was determined by Gas Chromatography-Mass Spectroscopy. The results were presented that E. montanum has antimicrobial activity against all tested microbial species except E. coli. Seventeen major chemical components were determined, but some composition of this sample is not match with library. For this reason, this medicinal plant contain unknown molecules and this molecules should be analysed by NMR spectra for 3D structure determination and identification.Article Citation - WoS: 15Citation - Scopus: 19Antimicrobial Activity and Chemical Composition Screening of Anacyclus Pyrethrum Root(Association of Pharmaceutical Teachers of India, 2017) Canlı, Kerem; Yetgin, Ali; Akata, Ilgaz; Altuner, Ergin MuratMedical herbs have many bioactive component and they are used in microbial treatment since ancient times. The resistance of pathogens to antibiotics became a critical problem, so researches for novel antimicrobial agents are required. Anacyclus pyrethrum (pellitory, Spanish chamomile or Mount Atlas daisy) is commonly used as a traditional medicine, therefore the antimicrobial activity of the root of this medicinal plant was investigated against 17 bacteria and 1 fungi by using disk diffusion method. The test strains include Bacillus, Enterobacter, Enterococcus, Escherichia, Klebsiella, Listeria, Pseudomonas, Salmonella, Staphylococcus and Candida genera. Besides, chemical composition of this sample was determined by Gas Chromatography-Mass Spectroscopy analysis. The results were presented that A. pyrethrum has antimicrobial activity against all tested microbial species except E. faecalis and S. typhimurium. Eighteen major chemical components were determined, but some composition of this sample is not match with library. For this reason, this medicinal plant contain unknown molecules and this molecules should be analysed NMR spectra for 3D structure determination and identification.Article Citation - WoS: 21Citation - Scopus: 19In vitro antimicrobial screening of Aquilaria agallocha roots(African Ethnomedicines Network, 2016) Canlı, Kerem; Yetgin, Ali; Akata, Ilgaz; Altuner, Ergin Muratackground: It was previously shown that some parts of Aquilaria agallocha, which is commonly known as oud or oodh, such as roots have been used as a traditional medical herbal in different countries. In Turkey A. agallocha is one of the ingredients while preparing famous Mesir paste, which was invented as a medicinal paste and used from the Ottoman period to now at least for 500 years. The identification the in vitro antimicrobial activity of ethanol extract of A. agallocha roots is main purpose of this analysis. Materials and Methods: By using 17 bacteria and 1 fungi, which include Bacillus, Candida, Enterobacter, Enterococcus, Escherichia, Klebsiella, Listeria, Pseudomonas, Salmonella and Staphylococcus genera, the activity of A. agallocha root extracts were analysed by the help of the disk diffusion method, that is one of the methods commonly used to determine antimicrobial activities. Results: As a result of the study it was observed that ethanol extracts of A. agallocha roots have a clear antimicrobial activity against nearly all microorganism used in the study, but only two bacteria namely E. coli ATCC 25922 and S. typhimurium SL 1344. Conclusion: According to the disk diffusion test results it may be possible to propose that A. agallocha roots should have a medicinal uses especially against E. faecium, L. monocytogenes ATCC 7644, B. subtilis DSMZ 1971, C. albicans DSMZ 1386, S. epidermidis DSMZ 20044 and S. aureus ATCC 25923.Article Citation - WoS: 30Citation - Scopus: 35Bioactive Sheath/Core Nanofibers Containing Olive Leaf Extract(John Wiley and Sons Inc., 2016) Doğan, Gamze; Başal, Güldemet; Bayraktar, Oğuz; Özyıldız, Figen; Uzel, Ataç; Erdoğan, İpekThis study aimed at producing silk fibroin (SF)/hyaluronic acid (HA) and olive leaf extract (OLE) nanofibers with sheath/core morphology by coaxial electrospinning method, determining their antimicrobial properties, and examining release profiles of OLE from these coaxial nanofibers. Optimum electrospinning process and solution parameters were determined to obtain uniform and bead-free coaxial nanofibers. Scanning electron microscopy and transmission electron microscopy (TEM) were used to characterize the morphology of the nanofibers. The antimicrobial activities of nanofibers were tested according to AATCC test method 100. Total phenolic content and total antioxidant activity were tested using in vitro batch release system. The quality and quantity of released components of OLE were determined by high-performance liquid chromatography. The changes in nanofibers were examined by Fourier-transform infrared spectroscopy. Uniform and bead-free nanofibers were produced successfully. TEM images confirmed the coaxial structure. OLE-loaded nanofibers demonstrated almost perfect antibacterial activities against both of gram-negative and gram-positive bacteria. Antifungal activity against C. albicans was rather poor. After a release period of 1 month, it was observed that ∼70-95% of the OLE was released from nanofibers and it was still bioactive. Overall results indicate that the resultant shell/core nanofibers have a great potential to be used as biomaterials.