Browsing by Author "Algul, Oztekin"

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2-Phenyl Substituted Benzimidazole Derivatives: Design, Synthesis, and Evaluation of Their Antiproliferative and Antimicrobial Activities
(Springer Birkhauser, 2022) Ersan, Ronak Haj; Kuzu, Burak; Yetkin, Derya; Alagoz, Mehmet Abdullah; Dogen, Aylin; Burmaoglu, Serdar; Algul, Oztekin
The inability to meet the desired outcomes of anticancer treatment and decrease in treatment success of bacterial and fungal infections accelerated research in these areas. Our research group has conducted numerous studies, especially on benzimidazole ring systems' antiproliferative and antimicrobial activities. In this study, the antiproliferative activity of benzimidazole compounds was tested against A549, A498, HeLa, A375, and HepG2 cancer cell lines by MTT assay. All compounds exhibited good to potent antiproliferative activity against all tested cancer cell lines. Compounds 6-chloro-2-(4-fluorobenzyl)-1H-benzo[d] imidazole (30) and 6-chloro-2-phenethyl-1H-benzo[d]imidazole (46) were especially active against HeLa and A375 cancer cell lines with IC50 values in the range of 0.02-0.04 mu M. In contrast, compounds 6-chloro-2-((p-tolyloxy)methyl)-1H-benzo[d] imidazole (67) and 5(6)-chloro-2-((4-hydroxyphenoxy)methyl)-1H-benzimidazole (68) were active against A549 and A498 cancer cell lines with an IC50 value of 0.08 mu M. These compounds (30, 46, 67, and 68) were less toxic to normal human cells than the positive control compound methotrexate, which was screened to determine its toxicity against normal cell lines (HEK293). In the second part of the study, all compounds were tested to demonstrate their antimicrobial properties. All compounds exhibited moderate activity against all tested bacteria and fungi. However, some phenoxy methyl derivatives 5-chloro-2-((4-chlorophenoxy)methyl)-1H-benzo[d]imidazole (69) and 5,6-dichloro-2-((4-chlorophenoxy)methyl)-1H-benzo[d] imidazole and (74) were most active against Candida (<3.90 mu g/mL). Molecular docking studies were carried out against certain proteins in order to identify potential targets of the antiproliferative effects of the synthesized compounds. The docking scores of the compounds were found to be significantly compatible with the antiproliferative activity results. [GRAPHICS] .
Design, Synthesis and in Vitro Antiproliferation Activity of Some 2-Aryl and -Heteroaryl Benzoxazole Derivatives
(Newlands Press Ltd, 2022) Kuzu, Burak; Hepokur, Ceylan; Turkmenoglu, Burcin; Burmaoglu, Serdar; Algul, Oztekin
Background: Phortress produces reactive electrophilic metabolites that form DNA adducts only in sensitive tumor cells. The authors converted the 2-phenylbenzothiazole nucleus in phortress to 2-aryl and -heteroaryl benzoxazole derivatives (11 new and 14 resynthesized). All synthesized compounds were studied for antitumor activity in various cancer cells. Materials & methods: Cytotoxicity, cell morphology, flow cytometry and cell-cycle analyses of compounds were performed and more active derivatives were tested in the MCF-7 cell line. Conclusion: Methyl 2-(thiophen-2-yl)benzo[d]oxazole-6-carboxylate (BK89) has a higher effect than fluorouracil to induce apoptotic cell death (apoptosis value of 49.44%). Cell-cycle analysis shows that the compounds BK89 and methyl 2-(furan-2-yl)benzo[d]oxazole-6-carboxylate (BK82) can be used as potential cell-cycle blockers by arresting MCF-7 cells in G0/G1 phase at rates of 63% and 85%, respectively. Plain language summary There is an urgent need to develop potent and selective anticancer agents. In this study, the design and applications of compounds sensitive to specific cancer cells and targeting cancer cells were investigated. The results show that the synthesized compounds can be antiproliferative drug candidates for breast cancer. These compounds may shed light on cancer treatment and cancer research.
Development of Benzoxazole Derivatives Targeting Mtor: a Promising Approach for Breast Cancer Therapy
(Wiley-V C H Verlag Gmbh, 2025) Alagoz, Mehmet Abdullah; Resitoglu, Meryem Temiz; Kuzu, Burak; Sabrie, Zainab; Yetkin, Derya; Zobi, Cengiz; Algul, Oztekin
Clinical use of mTOR inhibitors in cancer treatment is well established due to the critical role of mTOR signaling in tumor progression. In this study, we report the structure-based design and biological evaluation of a series of benzoxazole derivatives as potential mTOR inhibitors. Cytotoxicity studies using MTT assays showed that compounds B4, B11, B12, and B20 exhibited significant antiproliferative effects against breast cancer cell lines with IC50 values between 4.96 and 9.82 mu M. Colorimetric enzymatic assays further revealed that among these, only B12 and B20 effectively inhibited mTOR phosphorylation at Ser2448 in MCF-7 cells. Additionally, both compounds modulated the expression of key apoptotic proteins, including Bax, caspase-3, p53, and Bcl2. Molecular docking studies against the 4JT5 protein demonstrated binding affinities with docking scores ranging from -7.084 to -7.426 kcal/mol, comparable to the reference compound P2X (-7.309 kcal/mol). Molecular dynamics simulations over 150 ns confirmed the stability of B12 and B20 in the active site, with an average RMSD of 2.8 & Aring; and 3.0 & Aring;, respectively. The absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties of the synthesized compounds were evaluated in silico. Among them, B4, B11, B12, and B20 exhibited drug-like characteristics and showed no undesirable toxic effects. These findings highlight the potential of B12 and B20 as lead compounds for the development of novel mTOR inhibitors in breast cancer therapy.
Exploring New 5-Nitroimidazole Derivatives as Potent Acetylcholinesterase and Butyrylcholinesterase Enzyme Inhibitors
(Wiley-v C H verlag Gmbh, 2024) Gursoy, Sule; Satici, Doruk; Kuzu, Burak; Turkmenoglu, Burcin; Dilek, Esra; Algul, Oztekin
Discovering new compounds capable of inhibiting physiologically and metabolically significant drug targets or enzymes is of paramount importance in biological chemistry. With this aim, new 5-nitroimidazole derivatives (1-4) were designed and synthesized, and their inhibitory activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) were discovered using acetyl (butyryl) thiocholine and Ellman's reagents for spectrophotometric assay. The inhibitory profiles of the synthesized compounds were assessed by comparing their IC50 and Ki values. Results demonstrate significant inhibitory activity of all synthesized compounds against both AChE and BuChE compared to the reference compound, donepezil. Notably, compound 4 exhibited dual inhibition of these enzymes, showing the highest activity against Electrophorus electricus AChE (EeAChE) with a Ki value of 0.024 +/- 0.009 nM and against equine BuChE (eqBuChE) with a Ki value of 0.087 +/- 0.017 nM. Furthermore, molecular modeling was conducted to study the interaction modes of the most potent compound (4) and donepezil in the active site of their related enzymes' crystal structures (PDB ID: 4EY7 and 4BDS, respectively). Additionally, drug-likeness, ADME, and toxicity profiles of the compounds and metronidazole were predicted. The above results indicated that the dual inhibition of these enzymes is considered as a promising strategy for the treatment of neurological disorder especially Alzheimer's disease.
New-Generation Benzimidazole-Based Plasmid Delivery Reagents With High Transfection Efficiencies on the Mammalian Cells
(Springer, 2020) Ayaz, Furkan; Ersan, Ronak Haj; Kuzu, Burak; Algul, Oztekin
Gene transfer and gene therapy studies require high-efficiency gene delivery reagents. By transferring the piece of DNA that we are interested in, we can alter the expression of certain gene or genes to further characterize its role in the cell function or in the organism's development, metabolism, immune system, etc. Transfection reagents that enable efficient delivery of the DNA to the cells are important tools in the molecular and cellular biology studies. There are chemical products and tools that have been used for transfection of the cells but they are not as efficient as desired or they can induce cytotoxicity. It is crucial to design and generate new transfection reagents to further support the field of biotechnology, molecular studies, cellular biology, and in vitro studies relying on them. The more efficient and the less cytotoxic compounds will be especially useful for the field. We synthesized a new set of benzimidazole-based transfection reagents that have higher efficiency to carry GFP expressing plasmid in to the mammalian cells compared with the commercially available ones with low cytotoxicity. GFP expression levels were tracked by flow cytometry to determine the transfection efficiencies. Benzimidazole-based transfection reagents can be safely used for transfection studies in tissue culture as well as in gene therapy applications due to their high efficiency in the gene transfer to the mammalian cells.
Novel Oxalamide Derivatives for Coxs Expression and Breast Cancer: Design, Synthesis, Biological Evaluation, and Docking Studies
(Acg Publications, 2023) Kuzu, Burak; Hepokur, Ceylan; Algul, Oztekin
In the present study, new oxalamide-based compounds were designed from thalidomide and synthesized easily and with high yields (from 69% up to 93%) by a two-step method. The antiproliferative effects of synthesized 6a-d and 7a-d compounds on (ER+) MCF-7 and (ER-) MDA-MB-231 breast cancer cell line and human fibroblast WI-38 healthy cell line were investigated by the MTT method. The results showed that compound 7d was the most potent candidate against both MCF-7 and MDA-MB-231 cell lines with IC50 = 4.72 & mu;M and 6.37 & mu;M, respectively. To investigate whether antiproliferative effect of the compounds on breast cancer cell lines is dependent on COXs, expressions of COX-1/2 on the MCF-7 cell line were investigated by the Western-Blot technique. Among synthesized compounds, compound 7d increased the expression of both COX-1 and COX-2. The inhibition potential of compounds on COX-1/2 enzymes was investigated by molecular docking compared to inhibitor co-ligand celecoxib in crystal structures of COX-1 (PDB ID: 3KK6) and COX-2 (PDB ID: 3LN1). Docking results indeed showed that compound 7d had a higher binding affinity for both COX-1 and COX-2 active sites. Consequently, the novel oxalamide-based compounds presented here may be important candidate molecules for the development of new COX-dependent antiproliferative agents.& COPY;2023 ACG Publication. All right reserved.
Pyrrole-Tethered Bisbenzoxazole Derivatives: Apoptosis-Inducing Agents Targeting Breast Cancer Cells
(Wiley, 2025) Kuzu, Burak; Yetkin, Derya; Hepokur, Ceylan; Algul, Oztekin
This study presents the design, synthesis, and biological evaluation of a series of novel pyrrole-tethered bisbenzoxazole (PTB) derivatives as potential apoptosis-inducing agents targeting the MCF-7 human breast cancer cell line. The anticancer activity of these compounds was evaluated in vitro using the MTT assay, with tamoxifen serving as the reference therapeutic agent. Compounds B8, B14, and B18 demonstrated remarkable cytotoxicity against MCF-7 cells, exhibiting approximately 8-fold lower IC50 values compared to tamoxifen, while showing minimal effects on healthy fibroblasts. Further investigations revealed that these compounds effectively induced early-stage apoptosis and selectively arrested the cell cycle at the G1 phase in cancer cells. Gene expression analysis confirmed selective activation of the caspase-9-mediated apoptotic pathway in MCF-7 cells, providing insights into their underlying molecular mechanisms. These findings highlight the promising potential of PTB derivatives as potent anticancer agents, laying the groundwork for the development of targeted therapies for breast cancer that leverage apoptosis induction for improved therapeutic outcomes.
Structure-Based Inhibition of Acetylcholinesterase and Butyrylcholinesterase With 2-Aryl Benzoxazole Derivatives: Synthesis, Enzymatic Assay, and in Silico Studies
(Springer, 2025) Kuzu, Burak; Alagoz, M. Abdullah; Demir, Yeliz; Gulcin, Ilhami; Burmaoglu, Serdar; Algul, Oztekin
An important research topic is the discovery of multifunctional compounds targeting different disease-causing components. This research aimed to design and synthesize a series of 2-aryl-6-carboxamide benzoxazole derivatives that inhibit cholinesterases on both the peripheral anionic and catalytic anionic sides. Compounds (7-48) were prepared from 4-amino-3-hydroxybenzoic acid in three steps. The Ellman test, molecular docking with Maestro, and molecular dynamics simulation studies with Desmond were done (Schrodinger, 12.8.117). Compound 36, the most potent compound among the 42 new compounds synthesized, had an inhibitory concentration of IC50 12.62 nM for AChE and IC50 25.45 nM for BChE (whereas donepezil was 69.3 nM and 63.0 nM, respectively). Additionally, compound 36 had docking values of - 7.29 kcal/mol for AChE and - 6.71 kcal/mol for BChE (whereas donepezil was - 6.49 kcal/mol and - 5.057 kcal/mol, respectively). Furthermore, molecular dynamics simulations revealed that compound 36 is stable in the active gorges of both AChE (average RMSD: 1.98 & Aring;) and BChE (average RMSD: 2.2 & Aring;) (donepezil had average RMSD: 1.65 & Aring; and 2.7 & Aring;, respectively). The results show that compound 36 is a potent, selective, mixed-type dual inhibitor of both acetylcholinesterase and butyrylcholinesterase. It does this by binding to both the catalytically active and peripheral anionic sites of cholinesterases at the same time. These findings show that target compounds may be useful for establishing the structural basis for new anti-Alzheimer agents. [GRAPHICS] .
Synthesis of Benzoxazole-2 Derivatives: Electronic- and Position-Effect of Functional Groups and Computational Modeling of the Selectivity for Oxazole Ring
(Wiley-v C H verlag Gmbh, 2021) Kuzu, Burak; Sari, Ozlem; Erdem, Safiye Sag; Algul, Oztekin; Menges, Nurettin
In this study, Mitsunobu reagent, DEAD (diethyl azodicarboxylate) and PPh3, and ethyl-oxalamide derivatives of 2-aminophenol were reacted under mild reaction conditions. As a result of the cyclization reaction, benzoxazole derivatives bearing an ester group in the C-2 position were obtained in a one-pot protocol. It was observed that the electron-donating groups at the C-5 position and the electron-withdrawing groups at the C-6 position of the benzene ring increased the yield of the cyclic product. It was found that the cyclization does not occur when the carboxylic acid group is substituted in the benzene ring. The cyclization reaction we performed preferred the 5-endo-trig reaction instead of the 6-exo-trig. This experimental result was examined in detail with density functional theory (DFT) calculations as well. A computational exploration is presented herein that elucidates the detailed mechanism for Huisgen zwitterion's reaction with ethyl-oxalamide derivatives of 2-aminophenol. Potential alternative mechanisms were modeled with DFT calculations via CPCM/M06-2X/6-311++G(d,p)//B3LYP/6-31+G(d,p) level method in tetrahydrofuran to understand shed light on the mechanism. Our computational results are in good agreement with experimental findings that benzoxazole derivatives are the sole products in this reaction.
Synthesis of New Alicyclic Oxalamide Derivatives and Their Differential Immunomodulatory Activities on the Mammalian Cells
(Wiley, 2019) Kuzu, Burak; Ayaz, Furkan; Algul, Oztekin
A series of novel alicyclic oxalamide derivatives were synthesized by the reaction of the N-alicyclic secondary amine analogs with the intermediates obtained from the reaction of 2-aminophenol derivatives and diethyl oxalate. Due to their similarities to the thalidomide, these compounds were synthesized as alternative anti-inflammatory drug candidates. In order to test their efficacies, an in vitro inflammation model was utilized. In this model, macrophages be activated by a danger mimic lipopolysaccharide to produce pro-inflammatory cytokines. Macrophages are the major cell types that produce cytokines against danger stimuli to regulate the local as well as systemic immune reactions. The alicyclic oxalamide derivatives' immunomodulatory potentials were tested in vitro on the macrophages. Based on our results, these molecules had differential effects on the production of the TNF alpha and IL6 pro-inflammatory cytokines by the lipopolysaccharide-stimulated macrophages. A set of the derivatives had adjuvant and immunostimulatory activities, while another group had anti-inflammatory activities. Their differential effects on the production of the TNF alpha and IL6 open new venues for their medicinal applications. One can target a specific cytokine that has been associated with a certain disease while sparing the activity and production of the other cytokine by using a certain selection of the derivatives in our hands.
Synthesis, Biological Evaluation and in Silico Studies of Some 2-Substituted Benzoxazole Derivatives as Potential Anticancer Agents To Breast Cancer
(Wiley-v C H verlag Gmbh, 2022) Kuzu, Burak; Hepokur, Ceylan; Alagoz, Mehmet Abdullah; Burmaoglu, Serdar; Algul, Oztekin
In an attempt to develop potent and selective anticancer agents, some 5- or 6- and N-substituted benzoxazol-2-carboxamide derivatives were designed, synthesized, and evaluated for their cyclooxygenase inhibitory, antioxidant, and anti-proliferative activity against MCF-7 and MDA-MB-231 cell lines. Among them 5-OMe, N-piperidine substituted (compound 30), 5-OMe, N-4-methylpiperidine substituted (compound 31) and 5-Cl, N-piperidine substituted (compound 34) benzoxazole 2-carboxamide compounds have a moderate inhibitory effect in COX-1 and COX-2 enzymes. Anti-proliferative studies show that compound 30 (IC50=5.35 mu M) and compound 31 (IC50=5.82 mu M) have similar activity to reference drug 5-FU (IC50=3.95 mu M) on MCF-7 cell but they have lower toxic effect for healthy WI-38 cell line. For the MCF-7 cell line, compounds 30 and 31 show approximately 1.5 times higher selectivity compared to the 5-FU control. Among the synthesized compounds 30, 31, and 34 had the best anti-proliferative effect and were used to perform flow cytometry and cell cycle analysis on MCF-7 cell line. To predict the binding modes and pharmacokinetic parameters of all compounds, in silico studies were carried out. These compounds may shed light on cancer treatment and cancer research.