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Öğe A novel UA-CPME-FAAS method for simultaneous determination of Pb(II), Cd(II), and Cu(II) in grape and pomegranate samples using a bis (phthalimidoethyloxy)anthraquinone ligand(Academic Press Inc Elsevier Science, 2025) Mumcu, Taskin; Mumcu, Akin; Yilmaz, UlkuIn this study, a novel ultrasound-assisted cloud point microextraction (UA-CPME) method coupled with flame atomic absorption spectrometry (FAAS) was developed for the simultaneous determination of Pb(II), Cd(II), and Cu(II) ions in fruit samples. The extraction strategy employed synthesized 1,8-bis(phthalimidoethyloxy)anthraquinone ligand, used for the first time in a CPME system. Under optimized conditions, the metal-ligand complexes were efficiently extracted into the surfactant rich phase using the nonionic surfactant Triton X-100 at mild temperature and pH. The analytical performance of the method was remarkable, with low detection limits (0.6 mu g L-1 for Pb, 0.5 mu g L-1 for Cd, and 0.4 mu g L-1 for Cu), wide linear ranges (Pb: 0.7-350, Cd: 0.7-400, Cu: 0.5-400 mu g L-1), and excellent recoveries ranging from 95.6 % to 99.4 % with relative standard deviations below 2 %. The method was successfully applied to real grape and pomegranate juice samples, high recoveries and demonstrating minimal matrix effects. Matrix-matched calibration was not required, confirming the method's robustness and selectivity across different sample types. Furthermore, the use of a non toxic surfactant and elimination of organic solvents highlight the green and eco friendly nature of the method. Overall, the proposed UA-CPME-FAAS approach offers a simple, sensitive, cost effective, and environmentally sustainable solution for trace level multimetal analysis in complex food matrices such as fruit based samples.Öğe Activities of New Dinuclear PEPPSI-Precatalysts Bearing Bis-benzimidazole Ligands in the Suzuki-Miyaura Coupling Reaction(Wiley-V C H Verlag Gmbh, 2026) Yilmaz, Ulku; Gok, Yetkin; Aktas, AydinSeven new PEPPSI (Pyridine-Enhanced Precatalyst Preparation Stabilization and Initiation) type complex compounds containing bisbenzimidazole ligands were synthesized, and their structures were characterized by spectroscopic methods (1H, 13C-NMR, IR, HRMS). The catalytic activities of PEPPSI-precatalysts were tested in Suzuki-Miyaura cross-coupling reactions using phenylboronic acid, aryl bromides and aryl chlorides. It was observed that the precatalysts, having electron-dense benzimidazole ligands (compounds 1, 2), exhibited higher catalytic activity. In contrast, catalyst precursors having electron-poor benzimidazole ligands were found to have lower catalytic activity (compound 7).Öğe An evaluation on earthquakes and the changing chemical composition of Thymus sipyleus subsp. rosulans(Taylor & Francis Inc, 2025) Yilmaz, UlkuMajor earthquakes cause changes in ecological conditions in terms of soil, water and air content. In this study, the chemical content change of Thymus sipyleus (Boiss.) subsp. rosulans (Borbas) Jalas, an important medicinal aromatic plant used in folk medicine for the Ak & ccedil;ada & gbreve;-Malatya region, was determined after the severe twin earthquakes that occurred on February 6, 2023. The essential oils chemical contents of the plant aerial parts were identified by GC/MS analysis, naturally growing in Ak & ccedil;ada & gbreve;-Malatya, T & uuml;rkiye, which collected plant parts in April, May, and June months of 2022 and 2023. The major contents of the oil were determined as geranial (16.22-31.41%), neral (14.20-24.73%), and eucalyptol (3.32-17.23%). It was observed that the amounts of major components changed in the same months after the earthquake. In addition, ICP-MS analysis revealed that the amounts of some minerals (23Na,24Mg,39K, 44Ca, 66Zn, and 27Al) decreased in plant parts after the quake. As far as is known, this study is the first evaluation of this thymus species in the region.Öğe Anticancer and Antimicrobial Activities of New Cobalt and Zinc Complex-Derived Benzimidazole Containing Nitro or Methyl Groups(Amer Chemical Soc, 2026) Yilmaz, Ozgur; Apohan, Elif; Yesilada, Ozfer; Yilmaz, Ulku; Kucukbay, HasanThe cytotoxic effects of six newly synthesized 5(6)-methyl or 5(6)-nitrobenzimidazole-derived compounds that contain cobalt and zinc on nonsmall cell lung carcinoma (A549) and healthy lung epithelial (BEAS-2B) cell lines were evaluated by MTT, caspase-3, and Western Blotting methods. Cisplatin was also used as a reference compound. Compound 4 and compound 5 exhibited high cytotoxic activity against A549. While the IC50 value of cisplatin was 14.31 mu M, IC50 values of compound 4 and compound 5 were 10.30 and 7.01 mu M on A549 cells at 72 h, respectively. On the other hand, for BEAS-2B cells, the IC50 values of cisplatin, compound 4, and compound 5 were 5.91, 90.13, and 51,68 mu M, respectively. The results showed that although compounds 4 and 5 have high cytotoxicity on A549 cells, similar to cisplatin, they are less cytotoxic to BEAS-2B cells than cisplatin. The antibacterial and antifungal properties of the synthesized compounds were also investigated using minimum inhibitory concentration method. Their antimicrobial activities were tested against the Gram-negative bacteria Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853, Gram-positive Staphylococcus aureus ATCC 29213, and yeast species Candida albicans ATCC 90028 and Candida tropicalis. The compounds showed notable antimicrobial activity against these pathogenic bacteria and yeasts.Öğe Bisbenzimidazole salts and their in silico-in vitro inhibitory abilities on hCA I, hCA II, and AChE enzymes(Springer Wien, 2024) Yilmaz, Ulku; Demir, Yeliz; Tok, Tugba Taskin; Gok, Yetkin; Aktas, Aydin; Gulcin, IlhamiEight new bisbenzimidazolium halides were prepared from alkyl halides and 4,4 '-bis[(benzimidazol-1-yl)methyl]-1,1 '-biphenyl.The structures of the benzimidazole salts were characterized using elemental analysis techniques as well as 1H, 13C NMR, and FT-IR spectroscopic methods. The inhibitory effects of the benzimidazole derivatives were measured against human carbonic anhydrase I (hCA I), human carbonic anhydrase II (hCA II), and acetylcholinesterase (AChE) enzymes. All benzimidazolium halides exhibited significant enzyme inhibitory properties. They showed highly potent inhibitory effect on AChE and hCAs (Ki values are in the range of 15.7 +/- 0.8 to 49.7 +/- 10.1 nM, 14.6 +/- 1.5 to 70.7 +/- 2.7 nM, and 17.4 +/- 2.8 to 38 +/- 10 nM for AChE, hCA I, and hCA II, respectively). The binding orientation of the synthesized bisbenzimidazolium halides was evaluated by molecular docking studies, reflecting the importance of the p-methylbenzyl, m-methylbenzyl, p-nitrophenethyl, and 3-(1,3-dioxoisoindolin-2-yl)methyl) groups in protein-ligand interaction. The docking results support the Ki values of the respective compounds in this study. The structure-activity relationships against the various targets are clearly shown in three dimensions at the atomic level by their interactions with the mentioned enzymes.Öğe Emission based sensing of N-acetyl cysteine via silver equipped anthraquinone derivatives(Pergamon-Elsevier Science Ltd, 2026) Mumcu, Taskin; Oncuoglu, Serkan; Mumcu, Akin; Yilmaz, Ulku; Ertekin, KadriyeIn this work we investigated emission-based response of silver complexes of two newly synthesized anthraquinone derivatives for N-acetylcysteine (NAC) and thioglycolic acid. The interaction of the probes, DHAdibenzonitrile and DHA-dibutanenitrile with silver nanoparticles resulted in metal chelation and following quenching of the fluorescence. To determine whether the emission intensity of the complexes was re-stored again, thiol compounds; NAC and thioglycolic acid were used. The released dyes re-emitted light, allowing the system to exhibit an intensity-based turn-on type sensor behavior for the NAC and thioglycolic acid, respectively. The re-stored fluorescence was monitored as a strong emission based analytical signal at 560 nm. The complex stoichiometries were investigated using several approaches, including Job's plot, density functional theory (DFT) and FT-IR measurements. The findings relying on HOMO-LUMO and energy gap calculations highlight that Ag coordination and following acetylcysteine adduction significantly re-shape both local nucleophilic and electrophilic regions, modulating the global electronic structure and reactivity of anthraquinone derivatives. N-acetylcysteine exhibited an exceptional spectral response at pH 9.0 in a buffered solution exhibiting 13.6 and 14.4-fold enhancement in the emission intensity, respectively. The reported linear responses for a concentration range of; 1.0 x 10-5 M-1.0 x 10-2 M, can easily be adopted to determination of the NAC levels in drugs, in vitro studies or in serum samples. Limit of detection (LOD) and limit of quantification (LOQ) values of the DHA-dibutanenitrile derivative for the NAC molecule were found to be 1.28 x 10-6 and 1.21 x 10-5 mol x L-1, respectively. Similarly, the DHA-dibenzonitrile exhibited 1.11 x 10-6 and 1.28 x 10-5 mol x L-1 of LOD and LOQ values, respectively.Öğe Evaluation, synthesis and structural properties of stable bisbenzimidazolium tetrafluoroborates derived from unstable benzotetraazafulvalenes(Arkat Usa Inc, 2022) Yilmaz, Ulku; Kucukbay, HasanThe stable dicationic tetrafluoroborate salts of tetraazafulvalenes were synthesized with unstable N -heterocyclic carbenes or enetetramines derived from benzimidazolium and bridged-bisbenzimidazolium halides. The structural characterizations of all the compounds were determined via spectroscopic methods 1H-NMR, 13C-NMR, IR, and MS and by elemental analysis respectively. Also, the effect of compound 1 as a ligand on the catalytic system was evaluated in the Suzuki-Miyaura reaction.Öğe Synthesis of new anthraquinone compounds and evaluation of their considerable xanthine oxidase inhibitory activities(Arkat Usa Inc, 2022) Parladi, Ufuk; Yilmaz, Ulku; Noma, Samir Abbas Ali; Ates, Burhan; Kucukbay, HasanA series of anthraquinone derivatives (1-11) was prepared using alkyl halides, quinizarin, and danthron. The structural analysis of new compounds was carried out by 1H, 13C NMR, IR, and UV-Vis spectroscopic techniques. Xanthine oxidase inhibitory activities of compounds were measured using allopurinol as a standard. Inhibition abilities were identified by measuring the uric acid formation at 294 nm at 37 degrees C. According to the IC50 values of the compounds, it was observed that all the compounds in the group had higher inhibition values than allopurinol.
