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Öğe Indolyl imine compounds as multi-target agents; synthesis, antidiabetic, anticholinesterase, antioxidant activities and molecular modeling(Elsevier B.V., 2024) Ceyhan, Sadık M.; Zengin, İrem Nur; Bingül, Murat; Şahin, Hasan; Boǧa, Mehmet; Sağlam, Mehmet F.; Kandemir, HakanA new range of indolyl imine system 3d-l has been successfully prepared from 4,6-dimethoxy-2,3-diphenyl-indole-7-carbaldehyde 2a and 4,6-dimethoxy-3-aryl-indole-7-carbaldehyde 2b-c via Schiff base reaction. The structure of targeted compounds was confirmed by 1H and 13C NMR, FT-IR, mass spectrometry and single crystal X-ray diffraction techniques. The indolyl imine derivatives were also subjected to in vitro antidiabetic activities employing ?-glucosidase and ?-amylase enzymes. In terms of antidiabetic investigation, the ?-glucosidase enzyme was found to be potential target due to the comparable inhibition concentrations with the standard acarbose and the compound 3e exhibited better potency than the standard. The anticholinesterase potency of the compounds was investigated towards the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. The compounds displayed moderate efficiency against the BChE enzyme with the best inhibition concentration of 30.48 ?M by the compound 3h. The antioxidant properties of final compounds were determined by DPPH radical scavenging, ABTS Cation Radical Decolarization and CUPRAC Cupric Reducing Antioxidant Capacity assay methods. The ABTS cation scavenging assay provided the best responses for the compounds and the candidates 3k and 3l were determined as promising targets for the antioxidant activity. Plausible binding mode and interaction of ligands with the selected enzyme have been studied by molecular docking, supporting the experimental results. In silico ADME showed high drug likeness of the synthesized compounds. © 2024 Elsevier B.V.Öğe Synthesis of a novel N,N?,N?-tetraacetyl-4,6-dimethoxyindole-based dual chemosensor for the recognition of Fe3+ and Cu2+ ions(Elsevier Science Sa, 2019) Senkuytu, Elif; Bingul, Murat; Saglam, Mehmet F.; Kandemir, Hakan; Sengul, Ibrahim F.A novel N,N'N',1-tetraacetyl-4,6-dimethoxy-1H-indole-2-carbohydrazide 5, bearing four N-acetyl groups (N-COCH3) as cation binding sites was successfully synthesized by the reaction of readily available 4,6-dimethoxy-1H-indole-2-carbohydrazide 4 with acetic anhydride in dimethyl formamide in the presence of triethylamine. The structure of the acetyl indole 5 was confirmed using H-1 NMR, C-13 NMR, FT-IR, mass spectrometry and single crystal X-ray diffraction techniques. The colorimetric sensing ability of targeted compound 5 was investigated by monitoring UV-Vis and fluorescence spectroscopy spectral changes upon addition of different cations. The compound 5 demonstrated selective recognition toward the Fe+3 and Cu+2 ions over other cations examined such as Li+, Na+, K+ Mg2+, Ca2+, Ba2+, Mn2+, Fe2+, Cr3+, Co2+, Ni2+, Ag+, Cd2+, Al3+, Hg (+), Zn2+. The complex stoichiometry of the compound 5 and Cu2+/Fe3+ ions were determined as 2:1 (ligand/metal) by fluorescence titrations (Job's plot). This is the first report showing 4,6-dimethoxyindole moiety represents a dual chemosensor capable of detecting the Cu2+ and Fe2+ ions.Öğe Synthesis of furo[2,3-c]carbazoles as potent α-glucosidase and α-amylase inhibitors(Taylor and Francis Ltd., 2024) Uçar, Tuğçe N. Uslu; Bingül, Murat; Şahin, Hasan; Kandemir, Hakan; Şengül, İbrahim FazılThe carbazole-3-carbaldehyde 2, produced by N-ethyl carbazole via Vilsmeier-Haack reaction, was subjected to Dakin type oxidation with H2O2 and H2SO4 in methanol to produce the carbazole-3-ol 3. The reaction of 3 with a range of commercially available α-haloketones 4a–f in the presence of Al2O3 as catalyst in xylene led to their regio-selective cyclization to afford the furo[2,3-c]carbazoles 5a–f. Identification of the furo[2,3-c]carbazoles 5a–f were performed through 1H NMR,13C NMR, FT-IR and high resolution mass spectrometry. Single crystal X-ray diffraction analysis was employed to further confirm the structures of the some of the targeted compounds. In vitro antidiabetic activities of the newly synthesized furocarbazoles 5a–e were investigated utilizing α-glucosidase and α-amylase enzymes. The biological evaluation revealed the obvious efficiencies of the targeted molecules toward the α-glucosidase enzyme inhibition with the potent IC50 values compared to the standard acarbose. In the case of α-glucosidase inhibition, the furo[2,3-c]carbazoles chloro substituted 5c and nitro substituted 5f were found to be more potent than acarbose with the values of 215.0 and 162.70 μM, respectively. On the other hand, the compound 5f was found to be only promising candidate for α-amylase enzyme but not as effective as the standard acarbose.Öğe Synthesis of indole-2-carbohydrazides and 2-(indol-2-yl)-1,3,4-oxadiazoles as antioxidants and their acetylcholinesterase inhibition properties(Springer Wien, 2019) Bingul, Murat; Saglam, Mehmet F.; Kandemir, Hakan; Boga, Mehmet; Sengul, Ibrahim F.A range of novel 4,6-dimethoxy-1H-indole-2-carbohydrazides was prepared starting from methyl 4,6-dimethoxy-1H-indole-2-carboxylate which underwent cyclodehydration to generate the corresponding 2-(indol-2-yl)-1,3,4-oxadiazole scaffolds in the presence of N,N-diisopropylethylamine and p-toluenesulfonyl chloride in acetonitrile. All novel compounds were fully characterized by H-1 NMR, C-13 NMR, FT-IR, and high-resolution mass spectroscopic data. Biological importance of the designated compounds was identified by employing three different antioxidant property determination assays, namely DPPH free radical scavenging, ABTS cationic radical decolarization, and cupric reducing antioxidant capacity (CUPRAC). The anticholinesterase properties were also evaluated by the acetylcholinesterase and butyrylcholinesterase enzyme inhibition assays. According to the results, the indole compounds possessing carbohydrazide functionality were found to be more promising antioxidant targets than the 2-(indol-2-yl)-1,3,4-oxadiazole systems. N'-Benzoyl-4,6-dimethoxy-1H-indole-2-carbohydrazide, a member of the dimethoxyindole-2-carbohydrazide group, demonstrated a better inhibition performance than the standards. Additionally, extremely important results were obtained in the anticholinesterase enzyme inhibition assays in the case of 2-(indol-2-yl)-1,3,4-oxadiazole derivatives. [GRAPHICS] .Öğe Synthesis, biologic properties, and molecular modeling studies of bis-indole based thiosemicarbazones(Springer, 2024) Ceyhan, Sadık M.; Bingül, Murat; Şahin, Hasan; Boǧa, Mehmet; Sağlam, Mehmet F.; Kandemir, Hakan; Şengül, İbrahim FazılThe Schiff base condensation reaction of thiosemicarbazides and methylene bridged 2,2′-bisindolylmethanes, prepared from the acid-catalyzed condensation of 3-aryl-4,6-dimethoxyindole-7-carbaldehydes and formaldehyde, produced a series of the targeted bis-indole based thiosemicarbazones. To explore the biological potential of the newly synthesized compounds, antidiabetic, anticholinesterase, and antioxidant activities were investigated. The structural derivatization carried out by the addition of bromophenyl ring at C3 position of the indole backbone increased the enzyme potency towards the anticholinesterase activity. Some of the targeted compounds showed selective the α-glucosidase enzyme inhibition activity. In addition to that, the inhibition concentrations were found to lower that the standard acarbose showing that they may be more efficient agents. Although most of the compounds were effective for the metal chelation capacities (CUPRAC), a couple of examples were found to be favorable for DPPH and ABTS assays. The presence of methyl substituted thiosemicarbazone tail with different indole back bones individually detected as promising targets for ABTS and DPPH activities. The compound methyl substituted thiosemicarbazone was also determined as the most potent agent with the 6 μM inhibition concentration toward CUPRAC assay. Molecular docking study was performed to support the experimental results. Graphical abstract: (Figure presented.)Öğe Synthesis, characterization, UV-Vis absorption and cholinesterase inhibition properties of bis-indolyl imine ligand systems(Elsevier, 2020) Saglam, Mehmet F.; Bingul, Murat; Senkuytu, Elif; Boga, Mehmet; Zorlu, Yunus; Kandemir, Hakan; Sengul, Ibrahim F.A number of bis-indolyl imine helical structures has successfully been synthesized employing Schiff base reaction conditions starting from 4,6-dimethoxy-2,3-diphenylindole with different o-phenyl diamines as pi-spacer bridged. The structures of targeted compounds were identified by FT-IR, mass, H-1 and C-13 NMR spectroscopy along with single crystal X-ray diffraction techniques. The ground state absorption properties of the bis-indolyl compounds were also investigated utilizing UV-Vis absorption spectroscopy. As the biological aspect of the synthesized compounds, the anticholinesterase potency was investigated towards the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. The highest inhibition was determined in the presence of compound 9 with the values of 89.21 and 96.06, better than standard Galantamine, for AChE and BChE, respectively. (C) 2020 Elsevier B.V. All rights reserved.Öğe Synthesis, in vitro and in silico evaluation of indole linked carbohydrazides and 1,3,4-oxadiazoles as new α-glycosidase inhibitors(Elsevier, 2025) Kocaman, Kubra; Bingul, Murat; Ceyhan, Sadik M.; Sahin, Hasan; Saglam, Mehmet F.; Kandemir, Hakan; Sengul, Ibrahim F.The Hemetsberger indole reaction afforded 6-methyl and methoxy substituted indole-2-carboxylates 8 which were then reacted with an excess of hydrazine hydrate in ethanol to produce indole-2-carbohydrazides 9. Treatment of the compounds 9 with a range of commercially available benzoyl chlorides generated new indole linked diacyl hydrazines 10-15 and the corresponding cyclodehydration reaction in the presence of N,N-diisopropylethylamine (DIPEA) and p-toluenesulfonyl chloride (p-TsCl) in acetonitrile gave the targeted indole linked 1,3,4-oxadiazoles 16-21. The antidiabetic properties of the newly synthesized compounds were evaluated by employing alpha-glycosidase and alpha-amylase enzyme inhibition assays and the targeted compounds showed a range of inhibitory activities against alpha-glycosidase and alpha-amylase. The study revealed that the compounds selectively inhibit alpha-glycosidase enzyme. The detection of selective inhibition behaviours for alpha-glycosidase enzyme increased the novelty of the study and most of the IC50 values against the designated enzyme were found to be better than the standard acarbose. The structure-activity relation study illustrated that the oxadiazole ring with the methyl substituted indole and nitro substituted benzene rings demonstrated the best inhibition towards the alpha-glycosidase enzyme. The detected IC50 value for the identified compound 21 was found to be better (>25-fold) than the standard acarbose.Öğe Synthesis, photophysical and antioxidant properties of carbazole-based bis-thiosemicarbazones(Springer, 2019) Bingul, Murat; Senkuytu, Elif; Saglam, Mehmet F.; Boga, Mehmet; Kandemir, Hakan; Sengul, Ibrahim F.Utilizing Schiff base condensation of the 9-ethylcarbazole-3,6-dicarbaldehyde and thiosemicarbazides, four new N-ethylcarbazole-based bis-thiosemicarbazone compounds 4a-d were successfully synthesized in high yields. The photophysical properties of the targeted compounds 4a-d were investigated using UV-vis absorption and fluorescence emission spectroscopy. The antioxidant properties of targeted compounds 4a-d were determined by DPPH radical scavenging, ABTS Cation Radical Decolarization and CUPRAC Cupric Reducing Antioxidant Capacity assay methods. Moreover, the anti-cholinesterase properties of designated compounds were investigated by the Acetylcholinesterase (Ach) and Butyrylcholinesterase (BCh) enzyme inhibition assays. The compound 4a was determined as a valuable candidate to be a potent antioxidant agent for the DPPH and ABTS assays. The compound 4d was found to be a target compound for the kinetic measurements to identify the mechanism of action in the area of anticholinesterase activity assay.Öğe Synthesis, photophysical and antioxidant properties of pyrrolo[3,2-c]carbazole and dipyrrolo[3,2-c:2,3-g]carbazole compounds(Springer, 2019) Bingul, Murat; Senkuytu, Elif; Boga, Mehmet; Uslu, Tugce Nur; Kandemir, Hakan; Sengul, Ibrahim F.The synthesis of (6-ethyl-1,6-dihydropyrrolo[3,2-c]carbazol-2-yl)methanol 5 and (6-ethyl-6,11-dihydro-1H-dipyrrolo[3,2-c:2,3-g]carbazole-2,10-diyl)dimethanol 6 were achieved via the reduction of methyl pyrrolo carbazole carboxylate 3 and methyl dipyrrolo carbazole carboxylate 4, respectively. The structures of hydroxymethyl-pyrrolocarbazoles 5 and 6 were supported by FT-IR, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, H-1 and C-13 NMR spectroscopy. The photophysical properties of the targeted compounds 3-6 were investigated by employing absorption and fluorescence spectroscopy in different common organic solvents. Also, the fluorescence lifetime ((F)) of the compounds was measured utilizing a time-correlated single-photon counting technique in tetrahydrofuran. Antioxidant activities of compounds 3-6 were determined by employing three different assays, namely DPPH radical scavenging, ABTS cation radical decolarization and cupric reducing antioxidant capacity. The results revealed that the ABTS cationic scavenging activity assay was found to be the most sensitive method for the determination of inhibition values.Öğe Synthesis, reactivity and biological properties of methoxy-activated indoles(Society Chimica Italiana, 2021) Şengül, İbrahim F.; Bingül, Murat; Kandemir, Hakan; Kumar, Naresh; Black, David StC.; Attanasi, O.A.; Gabriele, B.; Merino, P.; Spinelli, D.Indoles continue to play a central role in the development of new structures of chemical and biological interest. They are the source of numerous biologically active natural products by virtue of their derivation from tryptophan units which are essential to peptide, protein and enzyme structures. Although the indole unit is electron rich and displays a wide range of reactivity, many naturally-occurring indoles contain methoxy substituents, which enhance their reactivity. The synthesis of methoxyindoles has also become a strategy for diversifying the regiochemical behaviour of indoles. This review brings together a wide range of information relating to indoles incorporating one, two, or three methoxy groups. It deals with aspects of synthesis, reactivity, and biological activity as well as summarizing the scope of important natural products.
