Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2025Phytochemical Profile, Antioxidant Capacity, Acetylcholinesterase, and Butyrylcholinesterase Enzyme Inhibition Properties of Myosotis amoena Boiss
Yapici, Ismail; Kayaoglu, Esma; Izol, Ebubekir; Yilmaz, Mustafa Abdullah; Behçet, Lutfi; Cakir, Oguz; Gülçin, Ilhami
Myosotis amoena Boiss. (Turkish name: Ho & scedil; boncukotu) is a perennial herbaceous plant that produces blue flowers during the spring. Phytochemicals, which are secondary metabolites distributed across plants, fungi, microorganisms, and even animal tissues, play crucial roles in health through their antioxidant and bioactive properties. Their antioxidant capacity largely arises from hydroxyl groups and aromatic ring structures that stabilize free radicals via electron delocalization. Enzyme inhibition is a therapeutic strategy in several diseases, including Alzheimer's disease (AD), where acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors are employed to manage symptoms. This study investigated the phytochemical composition (via LC-MS/MS), total phenolic content, antioxidant capacity, and AChE/BChE inhibitory effects of the ethanol extract of M. amoena using four in vitro methods. The CUPRAC assay demonstrated that M. amoena (1.070) exhibited higher antioxidant activity than Trolox (0.894), although its activity in FRAP, ABTS, and Fe3+ reduction assays was lower compared to standard antioxidants. The extract contained 53.03 mg GAE/g extract of total phenolics, with rosmarinic acid being the predominant compound (15.27 mg/g). Furthermore, the extract strongly inhibited AChE and BChE, with IC50 values of 3.9 and 19.8 mu g/mL, respectively. These findings highlight, for the first time, the significant bioactive potential of M. amoena as a natural source of antioxidants and cholinesterase inhibitors, supporting its prospective use in the prevention or management of neurodegenerative conditions.
- MakaleAçık Erişim20169,10-Dibromo-N-aryl-9,10-dihydro-9,10-[3,4]epipyrroloanthracene-12,14-diones: Synthesis and Investigation of Their Effects on Carbonic Anhydrase Isozymes I, II, IX, and XII
Göksu, Haydar; Topal, Meryem; Keskin, Ali; Gültekin, Mehmet S.; Çelik, Murat; Gülçin, Ilhami; Tanc, Muhammet; Supuran, Claudiu T.
N-substituted maleimides were synthesized from maleic anhydride and primary amines. 1,4-Dibromo-dibenzo[e,h]bicyclo-[2,2,2]octane-2,3-dicarboximide derivatives (4a-f) were prepared by the [4+2] cycloaddition reaction of dibromoanthracenes with the N-substituted maleimide derivatives. The carbonic anhydrase (CA, EC 4.2.1.1) inhibitory effects of the new derivatives were assayed against the human (h) isozymes hCA I, II, IX, and XII. All tested bicyclo dicarboximide derivatives exhibited excellent inhibitory effects in the nanomolar range, with Ki values in the range of 117.73-232.87 nM against hCA I and of 69.74-111.51 nM against hCA II, whereas they were low micromolar inhibitors against hCA IX and XII. A series of 9,10-dibromo-N-aryl-9,10-dihydro-9,10-[3,4]epipyrroloanthracene-12,14-diones (4a-f) were synthesized from N-substituted maleimide derivatives and 9,10-dibromoanthracene. Compounds 4a-f were assayed against human carbonic anhydrases (hCA) IX and XII, which are the two tumor-associated isozymes, and hCA I and II, which represent the most common off-targets for the development of selective anticancer CA inhibitors.
- MakaleAçık Erişim2016Antioxidant activity of taxifolin: An activity-structure relationship
Topal, Fevzi; Nar, Meryem; Gocer, Hulya; Kalin, Pinar; Kocyigit, Umit M.; Gülçin, Ilhami; Alwasel, Saleh H.
Taxifolin is a kind of flavanonol, whose biological ability. The objectives of this study were to investigate the antioxidants and antiradical activities of taxifolin by using different in vitro bioanalytical antioxidant methods including DMPD•+, ABTS•+, and DPPH•-scavenging effects, the total antioxidant influence, reducing capabilities, and Fe2+-chelating activities. Taxifolin demonstrated 81.02% inhibition of linoleic acid emulsion peroxidation at 30 μg/mL concentration. At the same concentration, standard antioxidants including trolox, α-tocopherol, BHT, and BHA exhibited inhibitions of linoleic acid emulsion as 88.57, 73.88, 94.29, and 90.12%, respectively. Also, taxifolin exhibited effective DMPD•+, ABTS•+, and DPPH•-scavenging effects, reducing capabilities, and Fe2+-chelating effects. The results obtained from this study clearly showed that taxifolin had marked antioxidant, reducing ability, radical scavenging and metal-chelating activities. Also, this study exhibits a scientific shore for the significant antioxidant activity of taxifolin and its structure-activity insight.
- MakaleAçık Erişim2016Acetylcholinesterase and carbonic anhydrase isoenzymes I and II inhibition profiles of taxifolin
Gocer, Hulya; Topal, Fevzi; Topal, Meryem; Küçük, Murat; Teke, Dilek; Gülçin, Ilhami; Alwasel, Saleh H.; Supuran, Claudiu T.
Taxifolin, also known as dihydroquercetin, is a flavonoid commonly found in plants. Carbonic anhydrase (CA, EC 4.2.1.1) plays an important role in many critical physiological events including carbon dioxide (CO2)/bicarbonate (HCO3-) respiration and pH regulation. There are 16 known CA isoforms in humans, of which human hCA isoenzymes I and II (hCA I and II) are ubiquitous cytosolic isoforms. In this study, the inhibition properties of taxifolin against the slow cytosolic isoenzyme hCA I, and the ubiquitous and dominant rapid cytosolic isoenzyme hCA II were studied. Taxifolin, as a naturally bioactive flavonoid, has a K-i of 29.2nM against hCA I, and 24.2nM against hCA II. For acetylcholinesterase enzyme (AChE) inhibition, K-i parameter of taxifolin was determined to be 16.7nM. These results clearly show that taxifolin inhibited both CA isoenzymes and AChE at the nM levels.
- MakaleAçık Erişim2015N-Acylsulfonamides strongly inhibit human carbonic anhydrase isoenzymes i and II
Yildirim, Alper; Atmaca, Ufuk; Keskin, Ali; Topal, Meryem; Çelik, Murat; Gülçin, Ilhami; Supuran, Claudiu T.
Sulfonamides represent a significant class of biologically active compounds that inhibit carbonic anhydrase (CA, EC.: 4.2.1.1) isoenzymes involved in different pathological and physiological events. Sulfonamide CA inhibitors are used therapeutically as diuretic, antiglaucoma, antiobesity and anticancer agents. A series of new sulfonamides were synthesized using imides and tosyl chloride as starting materials. These N-acylsulfonamides efficiently inhibited the cytosolic human carbonic anhydrase isoenzymes I, and II (hCA I, and II), with nanomolar range inhibition constants ranging between 36.4 ± 6.0-254.6 ± 18.0 and 58.3 ± 0.6-273.3 ± 2.5 nM, respectively.
- MakaleYalnız künye2014Synthesis and carbonic anhydrase inhibitory effects of novel sulfamides derived from 1-aminoindanes and anilines
Akbaba, Yusuf; Bastem, Enes; Topal, Fevzi; Gülçin, Ilhami; Marasç, Ahmet; Göksu, Süleyman
Three 1-aminoindanes, four anilines and BnOH or t-BuOH were reacted with chlorosulfonyl isocyanate to give sulfamoyl carbamates. Pd-C catalysed hydrogenolysis reactions of carbamates or deprotection of the Boc group of the carbamates with CF3CO2H afforded seven novel sulfamides. Human carbonic anhydrase (hCA) isoenzymes I and II (hCA I and hCA II) were purified from fresh human blood erythrocytes with onestep affinity chromatography on Sepharose 4B-tyrosine-sulfanilamide. The inhibitory properties of the novel sulfamides on both isoenzymes were determined using the esterase activity with 4-nitrophenyl acetate (NPA) as substrate. The tested novel sulfamides derived from 1-aminoindanes and anilines effectively inhibited hCA I and II competitively in the nanomolar range. Among these compounds, the novel sulfamide derivative 17 showed themost potent inhibitory effect against hCA I (Ki: 153.88 nM), while sulfamide derivative 26 showed the highest inhibitory potential against hCA II (Ki: 117.80nM).
- MakaleAçık Erişim2014Oxidation of cyanobenzocycloheptatrienes: Synthesis, photooxygenation reaction and carbonic anhydrase isoenzymes inhibition properties of some new benzotropone derivatives
Güney, Murat; Coskun, Ahmet; Topal, Fevzi; Dastan, Arif; Gülçin, Ilhami; Supuran, Claudiu T.
The oxidation of some cyanocycloheptatrienes with CrO3 and pyridine was investigated and a few new nitrile functionalised benzotropone derivatives were obtained. Photooxygenation reaction of these products was also studied. The structures of the formed products were determined on the basis of NMR spectroscopy and the formation mechanism of unusual products was discussed. Human carbonic anhydrase isoenzymes I, and II (hCA I and hCA II) inhibition properties of nitrile functionalized new benzotropone derivatives were also studied. Both CA isozymes were inhibited in the low micromolar range by these nitrile functionalized benzotropone analogues. The newly synthesized benzotropone derivatives showed inhibition constants in the sub-micromolar range (2.51-4.06 mu M). The best hCA I inhibition was observed in 5H-benzocycloheptene-7-carbonitrile (K-1: 2.88 +/- 0.86 mu M). On the other hand, 5-oxo-5H-benzocycloheptatriene-7-carbonitrile showed the powerful inhibitory effect against hCA II (K-i: 2.51 +/- 0.34 mu M). (C) 2014 Elsevier Ltd. All rights reserved.
- MakaleYalnız künye2013Radical scavenging and antioxidant capacity of serotonin
Sarikaya, S. Beyza Öztürk; Gülçin, Ilhami
Serotonin is a monoamine neurotransmitter and biochemically derived from tryptophan. The present paper examines the in vitro antioxidant and radical scavenging capacity of serotonin using different in vitro methodologies. For the determination of antioxidant activity of serotonin, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging, 2,2́-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, total antioxidant activity determination by ferric thiocyanate, total reducing ability determination by Fe3+-Fe2+ transformation method, superoxide anion radical scavenging by riboflavin-methionine-illuminate system, H2O2 scavenging and ferrous ions (Fe +) chelating activities of serotonin were performed. Also, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α-tocopherol and trolox, a water-soluble analog of α-tocopherol, were used as the reference antioxidant radical scavenger compounds. Serotonin completely inhibited lipid peroxidation of a linoleic acid emulsion at 15 μg/mL concentration. On the other hand, the above mentioned standard antioxidants displayed inhibition of 92.2, 99.6, 84.6 and 95.6% on peroxidation of linoleic acid emulsion, respectively at the 45 μg/mL concentration. In addition, serotonin was effective in DPPH· scavenging, ABTS•+ radical scavenging, superoxide anion radical scavenging, H2O2 scavenging, ferric ions (Fe3+) reducing power and metal chelating on ferrous ions (Fe+) activities. Also, those various antioxidant activities were compared to BHA, BHT α-tocopherol and trolox as references antioxidant compounds.
- MakaleYalnız künye2011Polyphenol contents and antioxidant properties of medlar (Mespilus germanica L.)
Gülçin, Ilhami; Topal, Fevzi; Sarikaya, S. Beyza Öztürk; Bursal, Ercan; Bilsel, Gökhan; Gören, Ahmet C.
Medlar is the fruit of Mespilus germanica L. in the family of Rosaceae. The present study outlines that the native medlar (Mespilus germanica L.) fruits an extremely rich source of antioxidants. In this study, antioxidant and antiradical property of medlar fruits were evaluated. Total phenolics and flavonoids amounts in lyophilized extract of medlar (LEM) fruits were calculated as gallic acid and quercetin equivalents, respectively. Antioxidant and radical scavenging activity of LEM were investigated using different in vitro assays including 1,1-diphenyl-2-picryl-hydrazyl (DPPH·), N,N-dimethyl-p-phenylenediamine (DMPD•+), and superoxide anion radicals (O2•-) scavenging activity, hydrogen peroxide (H2O2), ferric ions (Fe 3+) and cupric ions (Cu 2+) reducing ability, Fe 3+ -TPTZ reducing ability, ferrous ions (Fe2+) chelating activity as trolox equivalent. In addition, quantitative amounts of caffeic acid, ferulic acid, syringic acid, ellagic acid, quercetin, α-tocopherol, pyrogallol, p-hydroxybenzoic acid, vanillin, p-coumaric acid, gallic acid and ascorbic acid in LEM were detected by high performance liquid chromatography and tandem mass spectrometry (LC-MS/MS). The presence of these antioxidant compounds can be considered as a quality parameter for edible medlar fruits.