Sürdürülebilir Kalkınma Amaçları
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- MakaleYalnız künye2026Synthesis, antioxidant, and antiurease activities of novel benzimidazole-based 1,3,4-thiadiazole derivatives
Gümrükçüoğlu, Taner İlker; Akgün, Hakan; Bektaş, Hakan; Sökmen, Bahar Bilgin; Menteşe, Emre
In this study, we report the synthesis and characterisation of five new benzimidazole-based 1, 3, 4-thiadiazole derivatives (5a–e) and the evaluation of their antioxidant and antiurease activities. The structures were confirmed by NMR (1H, 13C) and LC/TOF–MS analyses (spectra are given in the supplementary information). Biological assays (DPPH, ABTS, iron-reducing power, urease inhibition) revealed that compound 5e (bearing a 4-nitrophenyl substituent) exhibited the strongest urease inhibition (EC50 = 0.1296 ± 0.0260 µM), surpassing thiourea. One-way ANOVA revealed significant differences in urease inhibition between the compounds (p<0.001). Post-hoc Tukey tests confirmed that compound 5e was more effective than several other compounds. The compounds exhibited moderate and comparable antioxidant activities. The first SAR study shows that electron-withdrawing substituents increase urease inhibition, whereas electron-donating groups increase the reducing power. Comparison with earlier reported triazole analogues shows scaffold-dependent changes in bioactivity. These findings support thiadiazoles as promising dual-function agents for oxidative stress and urease-associated pathologies.
- MakaleAçık Erişim2016Separation and preconcentration of Pb(II) and Cu(II) ions via carrier element-free coprecipitation using an acetohydrazide derivative
Tümay, Süreyya Oǧuz; Yazar, Murat; Ozdeş, Duygü; Bektaş, Hakan; Duran, Celal
A new method based on the combination of carrier element-free coprecipitation and flame atomic absorption spectrometric determination has been investigated for simultaneous separation and preconcentration of Pb(II) and Cu(II) ions in some environmental solid and liquid samples. The 2-f3-(4-methylbenzyl)-4-[2-(1H-indol-3-yl)ethyl]-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-ylg -N'-(phenylmethylene) acetohydrazide (MITA) was utilized as an organic coprecipitating agent without using a carrier element for coprecipitation of the analyte ions. The effects of experimental conditions including aqueous solution pH, MITA quantity, sample volume, standing time, and centrifugation rate and time were investigated in detail and optimized. The influences of some foreign ions were also evaluated on the quantitative recoveries of the analyte ions. The preconcentration factors were 125 for both analyte ions. The detection limits were 1.32 μgL-1 and 0.47 μg L-1 for Pb(II) and Cu(II) ions, respectively, and the relative standard deviations (RSDs) were lower than 4% for both analyte ions. After the accuracy of the method was checked, it was applied to sea and stream water as liquid samples and waste tea and tobacco as solid samples to determine the levels of Pb(II) and Cu(II) ions.
- BildiriYalnız künye2012Acetohydrazide derivative for selective separation and preconcentration of Cu(II) ions by coprecipitation method without using a carrier element
Ozdes, Duygu; Duran, Celal; Bektaş, Hakan; Tufekci, Mehmet; Soylak, Mustafa
A simple and rapid procedure based on the combination of carrier element free coprecipitation (CEFC) and flame atomic absorption spectrometric (FAAS) determinations has been developed for selective separation and preconcentration of Cu(II) ions in some environmental solid (Turkish and import coffee) and liquid (sea and stream waters) samples. In this method, acetohydrazide derivative was used as an organic coprecipitant without adding any carrier element for coprecipitation of Cu(II) ions. The preconcentration factor was found to be 50, the limit of detection (LOD) was 0.31 μgL -1, while the relative standard deviation (RSD) was found to be 1.6% for Cu(II) ions.