Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2020RP-HPLC-UV Analysis of the Phenolic Compounds, Antimicrobial Activity Against Multi-Drug Resistant Bacteria and Antioxidant Activity of Fruit and Seed of Diospyros lotus L.
Akar, Zeynep; Karakurt, Aylin; Okumus, Funda; Cinemre, Sedanur; Duzgun, Azer Ozad; Akar, Bulent; Can, Zehra
The object of the present study was to investigate the antioxidant, antimicrobial activity and phenolic compounds of fruit and seeds of Diospyros lotus L. The fruits consumed by humans as nutrients were harvested from the plants that grow naturally in the province of Trabzon-Akçaabat, Eastern Black Sea Region of Turkey. The antioxidant activities of fruit and seeds of Diospyros lotus were determined by using four methods (% DPPH radical scavenging activity, FRAP antioxidant power determination, CUPRAC reducing antioxidant activity and total phenolic content (TPC) in five different proportion of methanol-water extracts. All extracts of fruit and seeds of D. lotus analyzed through whole antioxidant analysis methods showed significant antioxidant activity. In addition, antimicrobial activity of fruit and seeds extracted with DMSO was determined against seven standard bacteria and three multi-drug resistance clinical strains. Although fruit extracts did not have the antimicrobial activity against bacteria, seeds showed antimicrobial effect to both standard strains (Gram-negative and Gram-positive) and antibiotic resistance clinical isolates (Klebsiella pneumoniae carrying blaKPC, Acinetobacter baumannii, harboring blaOXA-23 gene and resistance to colistin, and multi-drug resistant Pseudomonas aeruginosa). MICs’ value of plant seed extracts for standard strains was 0.75-25 mg/mL and antibiotic resistant clinical bacteria were 12.5 and 25 mg/mL. Additionally, phenolic compounds in methanol extracts of fruit and seeds were also determined in by HPLC using 19 standards. Gallic acid and chrysin phenolic compounds were the major phenolic compounds in fruit and seeds, respectively.
- MakaleAçık Erişim2020Biological activities and phytochemical screening of ethanol extracts from adonis paryadrica (Ranunculaceae)
Ucuncu, Osman; Baltaci, Cemalettin; Akar, Zeynep; Duzgun, Azer Ozad; Cuce, Mustafa; Kandemir, Ali
In this study, secondary metabolite profiles of flower, leaf and root of Adonis paryadrica ethanolic extracts were performed by using a newly developed and validated LC-MS/MS method. For this purpose, the LC-MS/MS system was used for the quantitative and qualitative analysis of 37 phytochemicals. The main component of the flower, leaf and root extracts was the quinic acid (160, 111 and 64 mg/kg, respectively). Antioxidant activities were determined using methods such as DPPH (SC50, mg/mL), FRAP (µM TEAC), CUPRAC (µM TEAC), ABTS (SC50, mg/mL) and TPC (GAE, µg/mL). While the highest antioxidant activity value for FRAP, CUPRAC, ABTS and TPC methods was determined in the leaf part of the plant, this value was determined in the flower part for DPPH. The antibacterial effects of the plant extracts were determined by liquid microdilution and agar diffusion methods. As a result, antimicrobial effect of flowers, leaf and all sections of plant extracts were determined except plant root extracts which did not display any activity against bacteria. Antimicrobial activity of the plant flower extract was found to be higher especially against to P. vulgaris with 3.5 mg/mL MIC.
- MakaleYalnız künye2017Molecular docking analysis and determination of minimum inhibition concentration of VIM-38/R228S
Duzgun, Azer Ozad; Saral, Aysegul
Objective: The aim of this study was to determine the effects of residues at 228th positions of VIM-38 on minimum inhibition concentration (MIC) and molecular docking analysis. Materials and methods: blaVIM-38 gene was cloned into expression vector pET100/D-TOPO. Then pET100/D-TOPO-VIM-38 was used to generate the R228S mutation by site-directed mutagenesis. The mutant was transformed into E. coli Dh5α. Changes in the activity of mutation R228S was determined by E-test. Molecular docking analysis of the binding affinity of meropenem and imipenem with VIM-38 and VIM-38 R228S was performed using AutoDock Vina_1_1_2. Results: According to E-test results, pET100/D-TOPO-VIM-38 and pET100/D-TOPO-VIM-38/ R228S have same MIC value for amoxicillin, ticarcillin/clavulanic acid, ampicillin and ticarcillin. It was determined decrease in pET100/D-TOPO-VIM-38/ R228S of MIC for aztreonam, amikacin and cefixine. There are 3-fold deference in MIC between pET100/D-TOPO-VIM-38 and pET100/D-TOPO-VIM-38/ R228S for cefoxitin. pET100/D-TOPO-VIM-38 has 0.5 µg/ml and pET100/D-TOPO-VIM-38/ R228S has 0.125 µg/m for imipenem, we observed 4-fold deference. Also, there is about 170-fold deference between pET100/D-TOPO-VIM-38 (16 µg/ml) and pET100/D-TOPO-VIM-38/ R228S (0.094 µg/ml) for meropenem. VIM-38 and VIM-38 R228S have very close to the negative low free energies of binding of the meropenem and imipenem. Conclusion: These results showed that substitution (R228S) slightly have effect on enzyme activity.
- MakaleAçık Erişim2016Kinetic characterization of GES-22 β-lactamase harboring the M169L clinical mutation
Saral, Aysegul; Leonard, David A; Duzgun, Azer Ozad; Cicek, Aysegul Copur; June, Cynthia M; Sandalli, Cemal
The class A β-lactamase GES-22 has been identified in Acinetobacter baumannii isolates in Turkey, and subsequently shown to differ from GES-11 by a single substitution (M169L). Because M169 is part of the omega loop, a structure that is known to have major effects on substrate selectivity in class A β-lactamases, we expressed, purified and kinetically characterized this novel variant. Our results show that compared with GES-116×His, GES-226×His displays more efficient hydrolysis of penicillins, and aztreonam, but a loss of efficiency against ceftazidime. In addition, the M169L substitution confers on GES-22 more efficient hydrolysis of the mechanistic inhibitors clavulanic acid and sulbactam. These effects are highly similar to other mutations at the homologous position in other class A β-lactamases, suggesting that this methionine has a key structural role in aligning active site residues and in substrate selectivity across the class.
- MakaleYalnız künye2014Characterization of novel VIM carbapenemase, VIM-38, and first detection of GES-5 carbapenem-hydrolyzing β-lactamases in Pseudomonas aeruginosa in Turkey
Iraz, Meryem; Duzgun, Azer Ozad; Cicek, Aysegul Copur; Bonnin, Remy A.; Ceylan, Aysenur; Saral, Aysegul; Nordmann, Patrice; Sandalli, Cemal
Pseudomonas aeruginosa isolates were collected form a Turkish hospital. Antimicrobial susceptibility was performed using the Vitek 2 Compact system, and 24 isolates were categorized as multidrug resistant (n = 18), extensively-drug resistant (n = 5), or pan-drug resistant (n = I). PCR and DNA sequence analysis revealed that 1 strain possessed the bla(GES-5) and another carried a novel bla(VIM) variant, named VIM-38. This new gene exhibited 1 amino acid substitution (Ala265Val) in comparison to its closest variant, VIM-5. Both VIM encoding genes were clones and demonstrated similar susceptibility profile when expressed in identical background. The presence of VIM-38 increases the diversity of carbapenemases in Turkey. (C) 2014 Elsevier Inc. All rights reserved.