Hayrettin Ozan Gulcan

Efficient Removal of Anionic and Cationic Dyes from an Aqueous Solution Using Pullulan-graft-Polyacrylamide Porous Hydrogel

A pullulan-graft-polyacrylamide porous hydrogel was prepared by radical polymerization in the presence of a crosslinking agent (N,N′-methylenebisacrylamide). Then, the swelling behavior of the hydrogel and the kinetics of swelling were investigated. The novel synthesized hydrogel was used as an adsorbent for removal of dyes from aqueous solutions. In this study, methylene blue (MB) and reactive blue 2 (RB) were selected as representative cationic and anionic dyes, respectively. The synthesized porous hydrogel exhibited excellent adsorption ability for both dyes. Various experimental conditions affecting the dye adsorption were explored to achieve maximum removal of both dye molecules. In addition, kinetic, thermodynamic, and adsorption isotherm models were employed to describe the dye adsorption process. The results indicated that the prepared hydrogel is an efficient adsorbent for dyes and possesses the ability to be regenerated without losing its original activity and stability for water treatment applications.

Design, synthesis and biological evaluation of novel 6H-benzo[c]chromen-6-one, and 7,8,9,10-tetrahydro-benzo[c]chromen-6-one derivatives as potential cholinesterase inhibitors

Hydroxylated 6H-benzo[c]chromen-6-one derivatives (i.e., urolithins) are the main bioavailable metabolites, and biomarkers of ellagitannins present in various nutrition. Although these dietaries, the sources of urolithins, are employed in folk medicine as cognitive enhancer in the treatment of Alzheimers Disease, urolithins have negligible potential to inhibit acetylcholinesterase and butyrylcholinesterase enzymes, the validated targets of Alzheimers Disease. Therefore, within this research, a series of 6H-benzo[c]chromen-6-one, and 7,8,9,10-tetrahydro-benzo[c]chromen-6-one derivatives has been designed, synthesized, and their biological activities were evaluated as potential acetylcholinesterase and butyrylcholinesterase inhibitors. The compounds synthesized exerted comparable activity in comparison to rivastigmine, galantamine, and donepezil both in in vitro and in vivo studies.

High-Performance Nanocatalyst for Adsorptive and Photo-Assisted Fenton-Like Degradation of Phenol: Modeling Using Artificial Neural Networks

High-performance activated carbon-zinc oxide (Ac–ZnO) nanocatalyst was fabricated via the microwave-assisted technique. Ac–ZnO was characterized and the results indicated that Ac–ZnO is stable, had a band gap of 3.26 eV and a surface area of 603.5 m2g−1, and exhibited excellent adsorptive and degrading potentials. About 93% phenol was adsorbed within 550 min of reaction by Ac–ZnO. Impressively, a complete degradation was achieved in 90 min via a photo-Fenton/Ac–ZnO system under optimum conditions. An artificial neural network (ANN) model was developed and applied to study the relative significance of input variables affecting the degradation of phenol in a photo-Fenton process. The ANN results indicate that increases in both H2O2 and Ac–ZnO dosage enhanced the rate of phenol degradation. The highest rate constant at the optimum conditions was 0.093 min−1 and it was found to be consistent with the ANN-predicted rate constant (0.095 min−1).

Traditional Techniques Applied in Olive Oil Production Results in Lower Quality Products in Northern Cyprus

Objectives: Olive oil production and its consumption is one of the traditional characteristics of Northern Cyprus. To date, no research has been conducted to analyze the quality of traditionally produced olive oil. Therefore, within this study, we aimed to analyze the olive oil produced within the island concomitant to the determination and comparison of its quality indices. Materials and Methods: The standard olive oil analysis techniques acknowledged by the IOOC and ISO were employed. Accordingly, the fatty acid content, peroxide level, total phenol content, the levels of carotenoids and chlorophyll, as well as status of oxidation were all tested concomitant to statistical analysis. Results: In contrast to the regional belief and consideration, the results indicated that the olive oil produced locally is highly exposed to oxidation and therefore, it is of lower quality according to the ISO guidelines. Conclusion: The traditional techniques employed for the production, distribution, and storage of olive oil within Northern Cyprus must be re-evaluated and controlled to satisfy the current standards required and employed globally.

Design, Synthesis and Investigation of New Diphenyl Substituted Pyridazinone Derivatives as Both Cholinesterase and Aβ-Aggregation Inhibitors

BACKGROUND With respect to the increase in the average life expectancy, Alzheimer Disease (AD), the most common form of age-related dementia, has become a major threat to the population over the age of 65 during the past several decades. The majority of AD treatments are focused on cholinergic and amyloid hypotheses. OBJECTIVE In this study, three series of diphenyl-2-(2-(4-substitutedpiperazin-1-yl)ethyl)pyridazin- 3(2H)-one derivatives were designed, synthesized and investigated for their ability to inhibit both cholinesterase enzymes and amyloid-β aggregation. METHOD The inhibitory activities of the synthesized compounds on AChE (from electric eel) and BChE (from equine serum) were determined by the modified Ellmans method. The reported thioflavin T-based fluorometric assay was performed to investigate the effect of the selected compounds on the aggregation of Aβ1-42. The cytotoxic effect of the compounds (4g, 11g and 18g) was monitored in 3T3 cell lines to gain insight into therapeutic potential of the compounds by using MTT assay. The crystal structures of the AChE (1EVE) and BChE (1P0I) enzymes were retrieved from the RCSB Protein Data Bank and Molecular Operating Environment (MOE) software was used for molecular docking of the ligands. RESULTS Among the tested compounds, 5,6-diphenyl derivative 18g was identified as the most potent and selective AChE inhibitor (IC50 = 1.75 µM, Selectivity Index for AChE > 22.857). 4,6- Diphenyl derivative 11g showed the highest and the most selectivity for BChE (IC50= 4.97 µM, SI for AChE < 0.124). Interestingly, 4,5-diphenyl derivative 4g presented dual cholinesterase inhibition (AChE IC50= 5.11 µM; BChE IC50= 14.16 µM, SI for AChE = 2.771). CONCLUSION Based on biological activity results and low toxicity of the compounds, it can be said that diphenyl substituted pyridazinone core is a valuable scaffold. Especially, dual inhibitory potencies of 4,5-diphenylpyridazin-3(2H)-one core for the cholinesterase enzymes and Aβ- aggregation makes this core a promising disease-modifying agent.

Urolithin B as a Simple, Selective, Fluorescent Probe for Sensing Iron(III) in Semi-Aqueous Solution

The development of simple, environmental friendly, and cheap reagents with metal binding properties are quite important not only for the treatment of environmental pollution but also for their application in medicine. Within this study, for the first time, we displayed a natural chromen analogue, Urolithin B, as a simple, selective, fluorescent iron (III) sensing probe. Following the synthesis and structure identification studies, the selective metal binding property of the compound was displayed employing fluorescence techniques. Accordingly, urolithin B has the capacity to coordinate selectively to iron (III) with a 3:2 stoichiometry.

Design and synthesis of some new carboxamide and propanamide derivatives bearing phenylpyridazine as a core ring and the investigation of their inhibitory potential on in-vitro acetylcholinesterase and butyrylcholinesterase

A series of new carboxamide and propanamide derivatives bearing phenylpyridazine as a core ring were designed, synthesized and evaluated for their ability to inhibit both cholinesterase enzymes. In addition, a series of carboxamide and propanamide derivatives bearing biphenyl instead of phenylpyridazine were also synthesized to examine the inhibitory effect of pyridazine moiety on both cholinesterase enzymes. The inhibitory activity results revealed that compounds 5b, 5f, 5h, 5j, 5l pyridazine-3-carboxamide derivative, exhibited selective acetylcholinesterase (AChE) inhibition with IC50 values ranging from 0.11 to 2.69 µM. Among them, compound 5h was the most active one (IC50 = 0.11 µM) without cytotoxic effect at its effective concentration against AChE. Additionally, pyridazine-3-carboxamide derivative 5d (IC50 for AChE = 0.16 µM and IC50 for BChE = 9.80 µM) and biphenyl-4-carboxamide derivative 6d (IC50 for AChE = 0.59 µM and IC50 for BChE = 1.48 µM) displayed dual cholinesterase inhibitory activity. Besides, active compounds were also tested for their ability to inhibit Aβ aggregation. Theoretical physicochemical properties of the compounds were calculated by using Molinspiration Program as well. The Lineweaver-Burk plot and docking study showed that compound 5 h targeted both the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE.

Synthesis of Novel Benzothiazole-Piperazine Derivatives and Their Biological Evaluation as Acetylcholinesterase Inhibitors and Cytotoxic Agents

OBJECTIVE AND METHOD A new series of benzothiazole-piperazine derivatives was synthesized and a complete chemical characterization of the novel compounds was provided. In vitro cytotoxic activities were screened against colorectal (HCT-116), breast (MCF-7) and hepatocellular (Huh7) cancer cell lines by Sulforhodamine B assay. RESULT AND DISCUSSION All compounds showed cytotoxic activity against hepatocellular (Huh7) and breast (MCF-7) cancer cell lines. Dihalo substituted benzylpiperazine derivatives (2a, 2e) had the highest cytotoxic activities in all the tested cell lines. In addition, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activities of synthesized compounds were investigated by in vitro Ellmans method. Compound 2j led to moderate and selective inhibition against AChE. Docking study was utilized to understand the binding mode of compound 2j in comparision with donepezil on AChE. The other tested compounds showed weak or no inhibition against AChE as promising anticancer agents.

Marginally designed new profen analogues have the potential to inhibit cyclooxygenase enzymes.

The current structure–activity relationship of profens (i.e., 2‐arylpropionic acid derivatives, a class of non‐steroidal anti‐inflammatory drugs) discusses the importance of α‐monomethyl substitution on these compounds, since the activities obtained through their corresponding arylacetic acid derivatives (i.e., α‐demethylated derivatives) or α,α‐dimethyl‐substituted compounds are less than what is observed for the parent profens. Unfortunately, this implies a generalization in structure–activity relationships of profens in such a way that a mono‐(non‐methyl)alkyl group or dialkyl substituent replaced at the α‐position of a profen analogue results in abolished activity. Therefore, within this study, we aimed to question this generalization employing ibuprofen, flurbiprofen, and naproxen as model compounds. A series of α‐(non‐methyl)alkyl‐substituted ibuprofen and flurbiprofen analogues as well as α,α‐dialkyl‐substituted ibuprofen, flurbiprofen, and naproxen derivatives were synthesized and screened for their potential to inhibit cyclooxygenase enzymes. In addition, since profens have negligible potential to inhibit lipoxygenase enzymes, the effect of such derivatization was also questioned in lipoxygenase inhibition assays. The findings only partially agreed with the current structure–activity approach of profens and the activity results of some compounds were found as beyond ordinary.