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GÖREN, AHMET CEYHAN

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AHMET CEYHAN
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Start date: 2010 × End date: 2019 × Author: GÜLÇİN, İlhami ×

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    Sage (Salvia pilifera): determination of its polyphenol contents, anticholinergic, antidiabetic and antioxidant activities
    (2019-09-01) GÜLÇİN, İlhami; Tel, Ahmet Zafer; GÖREN, AHMET CEYHAN; Taslimi, Parham; Alwasel, Saleh H.; GÖREN, AHMET CEYHAN
    In this work, we determined for the first time the Salvia pilifera Montbret & Aucher ex Bentham as an important source for natural products with antioxidant and antidiabetic potentials. In this context, methanol (MESP) and water (WESP) extracts were prepared from aerial parts of S. pilifera. Also, it was evaluated for antioxidant profile by eight distinguishes bioanalytical methods and inhibition effects against enzymes linked to different diseases, namely butyrylcholinesterase (BChE), acetylcholinesterase (AChE), alpha-glycosidase and alpha-amylase. Also, the polyphenolic compositions of MESP and WESP were evaluated by high performance liquid chromatography and tandem mass spectrometry (LC-MS/MS). Fourteen phenolics were identified in the evaporated MESP and thirteen phenolic compounds were identified in the lyophilized WESP. Also, we performed the antioxidant properties of both extracts. In order to estimate the capacity of MESP and WESP to act as antioxidants, 1,1-diphenyl-2-picryl-hydrazyl radicals (DPPH center dot), 2,2 --azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radicals (ABTS(center dot+)) and N,N-dimethyl-p-phenylenediamine radicals (DMPD center dot+), scavenging activities, ferric ions (Fe3+), Fe3+-TPTZ and cupric ions (Cu2+) reducing assays were studied. MESP and WESP were found as potent effective DPPH center dot (IC50: 7.05 and 8.56 mu g/mL), ABTS(center dot+) (IC50: 3.52 and 4.76 mu g/mL) and DMPD center dot+ (IC50: 28.92 and 30.95 mu g/mL) scavenging effects. On the other hand, MESP and WESP showed the potent inhibition effects against AChE (IC50: 94.93 and 138.61 mu g/mL), BChE (IC50: 60.05 and 99.13 mu g/mL), alpha-glycosidase (IC50: 23.28 and 36.47 mu g/mL) and alpha-amylase (IC50: 46.21 and 97.67 mu g/mL) enzymes. This study will be an innovative and guider for further studies for antioxidant properties for industrial or medicinal plants.
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    Antioxidant activity and polyphenol content of cherry stem (Cerasus avium L.) determined by LC-MS/MS
    (2013-04-01T00:00:00Z) Bursal, Ercan; KÖKSAL, EKREM; GÜLÇİN, İlhami; BILSEL, Gokhan; Goren, AHMET CEYHAN; GÖREN, AHMET CEYHAN
    In this study, the antioxidant and antiradical properties of cherry stem (Cerasus avium L.) were examined. The ferric thiocyanate method, ferric ion (Fe3+) and cupric ion (Cu2+) reducing assays and ferrous ions (Fe3+) chelating assay were used in order to measure the antioxidant activity of the plant. Also, its antiradical activity was measured by 1,1-diphenyl-2-picryl-hydrazyl (DPPH center dot) radical scavenging activity. Additionally, total phenolic and flavonoid contents of the plant were determined. It was indicated that, both the water extract of cherry stem (WECS) and ethanol extract of cherry stem (EECS) have both antioxidant and antiradical properties, and there is a correlation between these properties and the phenolic and flavonoid contents. Quantities of caffeic acid, ferulic acid, syringic acid, ellagic acid, quercetin, alpha-tocopherol, pyrogallol, p-hydroxybenzoic acid, vanillin, p-coumaric acid, gallic acid and ascorbic acid were detected by high performance liquid chromatography and tandem mass spectrometry (LC-MS/MS). This study will bring an innovation for further studies conducted on the antioxidant properties of WECS and EECS. (C) 2012 Elsevier Ltd. All rights reserved.
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    Polyphenol Contents and Antioxidant Properties of Medlar (Mespilus germanica L.)
    (2011-01-01T00:00:00Z) GÜLÇİN, İlhami; Topal, Fevzi; Sarikaya, S. Beyza Ozturk; Bursal, Ercan; BILSEL, Gokhan; Goren, AHMET CEYHAN; GÖREN, AHMET CEYHAN
    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 (O-2(-)) scavenging activity, hydrogen peroxide (H2O2), ferric ions (Fe3+) and cupric ions (Cu2+) reducing ability, Fe3+-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, alpha-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.
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    Phytochemical content, antioxidant activity, and enzyme inhibition effect of Salvia eriophora Boiss. & Kotschy against acetylcholinesterase, alpha-amylase, butyrylcholinesterase, and alpha-glycosidase enzymes
    (2019-03-01) Bursal, Ercan; Aras, Abdulmelik; Kilic, Omer; Taslimi, Parham; Goren, AHMET CEYHAN; GÜLÇİN, İlhami; GÖREN, AHMET CEYHAN
    Many taxa of Salvia genus have been used in herbal beverages, food flavoring, cosmetics, and pharmaceutical industry. In this paper, chemical compounds of Salvia eriophora (S. eriophora) leaves were determined by LC-MS/MS (Liquid Chromatography tandem Mass Spectrometry). Salvigenin (158.64 +/- 10.8 mg/kg), fumaric acid (123.09 +/- 8.54 mg/kg), and quercetagetin-3.6-dimethylether (37.85 +/- 7.09 mg/kg) were detected as major compounds in the ethanol extract, whereas fumaric acid (555.96 +/- 38.56 mg/kg), caffeic acid (103.62 +/- 20.51 mg/kg), and epicatechin (83.19 +/- 8.43 mg/kg) were detected as major compounds in the water extract. Furthermore, enzyme inhibition of S. eriophora against acetylcholinesterase (AChE), alpha-amylase (AM), butyrylcholinesterase (BChE), and alpha-glycosidase (AG) enzymes were detected. AChE, BChE, AG, and AM enzymes were very strongly inhibited by S. eriophora water extract (WES) and S. eriophora methanol extract (MES). Additionally, antioxidant potential of S. eriophora was determined by in vitro analytical methods. IC50 values of WES and MES were performed for radicals.
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    A class of sulfonamides as carbonic anhydrase I and II inhibitors
    (2016-12-01T00:00:00Z) GOKCEN, Taner; GÜLÇİN, İlhami; OZTURK, Turan; Goren, AHMET CEYHAN; GÖREN, AHMET CEYHAN
    Four groups of novel sulfonamide derivatives: (i) acetoxybenzamide, (ii) triacetoxybenzamide, (iii) hydroxybenzamide and (iv) trihydroxybenzamide, all having thiazole, pyrimidine, pyridine, isoxazole and thiadiazole moieties were prepared and their inhibitory effects were studied on two metalloenzymes, i.e. carbonic anhydrase isozymes (hCA I and II), purified from human erythrocyte cells by Sepharose-4B-l-tyrosine-sulfanilamide affinity chromatography. These enzymes are present in almost all living organisms to catalyse the synthesis of bicarbonate ion (HCO3-) from carbon dioxide and water. The sulfonamide derivatives were found to be active against hCA I and II in the range of 2.62-136.54 and 5.74-210.58nM, respectively.
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    Antioxidant activity and phenolic compounds of ginger (Zingiber officinale Rosc.) determined by HPLC-MS/MS
    (2017-06-01T00:00:00Z) Tohma, Hatice; GÜLÇİN, İlhami; Bursal, Ercan; Goren, AHMET CEYHAN; ALWASEL, Saleh H.; KÖKSAL, EKREM; GÖREN, AHMET CEYHAN
    Oxidative stress related diseases often arise from over production of free radicals and reactive oxygen/nitrogen species. The prevention of these diseases could be possible with the use of natural antioxidant plants that could be promising as therapeutic candidates. Since antioxidant properties of a species could be stem from phenolic compounds, it is, therefore, important to evaluate antioxidant and total/individual phenolic and flavonoid content. For this purpose, we evaluated antioxidant properties of ginger (Zingiber officinale Rosc.) based on three parameters: the antioxidant capacity, total phenolic and flavonoid content as well as identification of phenolic acids of water extract (WEG) and ethanol extract (EEG) of ginger. For antioxidant capacity, we performed FRAP, CUPRAC assay, Fe2+ chelating ability, DPPH and DMPD radical scavenging activities. Also, total phenolic and flavonoid contents in both extracts were also measured via Folin Ciocalteu-s method. For identification of phenolic acids, HPLC-MS/MS method was performed. The results showed that EEG had generally better antioxidant activity than WEG in all assays. HPLC-MS/MS analysis showed that there are at least eight different phenolic acids found in ginger, among which pyrogallol p-hydroxybenzoic acid, ferulic acid and p-coumaric acid were more abundant in both extracts. This study clearly showed that ginger extracts demonstrated effective antioxidant properties and their consumption may reduce or delay the progression of diseases that oxidative stress take place due to lack of antioxidant supplementation.
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    Pomological Features, Nutritional Quality, Polyphenol Content Analysis, and Antioxidant Properties of Domesticated and 3 Wild Ecotype Forms of Raspberries (Rubus idaeus L.)
    (2011-05-01T00:00:00Z) GÜLÇİN, İlhami; Topal, Fevzi; Cakmakci, Ramazan; BILSEL, Mine; Goeren, AHMET CEYHAN; Erdogan, Ummugulsum; GÖREN, AHMET CEYHAN
    The raspberry (Rubus idaeus L.) is an economically important berry crop that contains many phenolic compounds with potential health benefits. In this study, important pomological features, including nutrient content and antioxidant properties, of a domesticated and 3 wild (Yayla, Yavuzlar, and Yedigol) raspberry fruits were evaluated. Also, the amount of total phenolics and flavonoids in lyophilized aqueous extracts of domesticated and wild ecotypes of raspberry fruits were calculated as gallic acid equivalents (GAEs) and quercetin equivalents (QE). The highest phenolic compounds were found in wild Yayla ecotype (26.66 +/- 3.26 GAE/mg extract). Whilst, the highest flavonoids were determined in wild Yedigol ecotype (6.09 +/- 1.21 QA/mg extract). The antioxidant activity of lyophilized aqueous extracts of domesticated and wild ecotypes of raspberry fruits were investigated as trolox equivalents using different in vitro assays including DPPH center dot, ABTS center dot+, DMPD center dot+, and O center dot-(2) radical scavenging activities, H2O2 scavenging activity, ferric (Fe3+) and cupric ions (Cu2+) reducing abilities, ferrous ions (Fe2+) chelating activity. In addition, quantitative amounts of caffeic acid, ferulic acid, syringic acid, ellagic acid, quercetin, alpha-tocopherol, pyrogallol, p-hydroxybenzoic acid, vanillin, p-coumaric acid, gallic acid, and ascorbic acid in lyophilized aqueous extracts of domesticated and wild ecotypes of raspberry fruits were detected by high-performance liquid chromatography and tandem mass spectrometry (LC-MS-MS). The results clearly show that p-coumaric acid is the main phenolic acid responsible for the antioxidant and radical scavenging activity of lyophilized aqueous extracts of domesticated and wild ecotypes of raspberry fruits.
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    Antioxidant activity and polyphenol content of Turkish thyme (Thymus vulgaris) monitored by liquid chromatography and tandem mass spectrometry
    (2017-01-01T00:00:00Z) KÖKSAL, EKREM; Bursal, Ercan; GÜLÇİN, İlhami; KORKMAZ, MUSTAFA; Caglayan, Cuneyit; Goren, AHMET CEYHAN; ALWASEL, Saleh H.; GÖREN, AHMET CEYHAN
    Like tea, the leaves of Turkish thyme (Thymus vulgaris) can be boiled in water to produce an extract. This is widely used as syrup for the treatment of coughs and bronchitis at alternative medicine clinics in many parts of the world. In the current study, we assessed the phenolic content and antioxidant activity of thyme. The antioxidant activities of both ethanol and aqueous extracts of thyme were determined using various in vitro methods. The total phenolic and total flavonoid contents were determined to be a gallic acid equivalent and a quercetin equivalent, respectively. Finally, the quantities of the phenolic compounds were detected using high-performance liquid chromatography and tandem mass spectrometry. The total phenolic compounds in the aqueous extract and ethanol extracts of Turkish thyme were 256.0 g gallic acid equivalent/mg dried extract and 158.0 g gallic acid equivalent/mg dried extract, respectively. Conversely, the total flavonoid compounds in both extracts were 44.2 g and 36.6 g quercetin equivalent/mg dried extract, respectively. For the first time, we determined phenolic contents and investigated the antioxidant potential of thyme. The results indicate that Turkish thyme is a good dietary source with phenolic properties.
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    Anticholinergic, antidiabetic and antioxidant activities of cinnamon (cinnamomum verum) bark extracts: polyphenol contents analysis by LC-MS/MS
    (2019-01-01) GÜLÇİN, İlhami; Kaya, Ruya; GÖREN, AHMET CEYHAN; Akincioglu, Hulya; Topal, Meryem; Bingol, Zeynebe; Cakmak, Kader Cetin; Sarikaya, Sevim B. Ozturk; DURMAZ, LOKMAN; Alwasel, Saleh; GÖREN, AHMET CEYHAN
    Ethanolic (EEC) and aqueous (WEC) extracts of cinnamon (Cinnamomum verum) were evaluated for their antioxidant profiles by eight distinguished bioanalytical antioxidant methods. Their inhibitory effects were tested against some enzymes including acetylcholinesterase, butyrylcholinesterase, alpha-glycosidase and alpha-amylase, which linked to different diseases. Additionally, the antioxidant properties were determined and polyphenolic compositions of the both extracts were evaluated by LC-MS/MS analysis. According to the LC-MS/MS experiments, thirteen compounds were found in WEC and EEC. Also, p-hydroxybenzoic acid (321.1 mg/kg extract), p-coumaric acid (291.4 mg/kg extract), and pyrogallol (142.4 mg/kg extract) were found to be the most abundant ingredients in the WEC. On the other hand, pyrogallol (264.3 mg/kg extract), ferulic acid (224.7 mg/kg extract) and p-coumaric acid (170.2 mg/kg extract) were found as the most plentiful chemicals in the EEC. For the estimation of the antioxidant capacities of the both extracts (WEC and EEC), DPPH center dot and ABTS(center dot+) scavenging activities, as well as Fe3+-Fe2+, and Cu2+-Cu+ reducing assays were studied. The IC50 values of the WEC and EEC indicated that they were potent effective DPPH center dot (21. 25 and 15.71 mu g/mL) and ABTS(center dot+) (6.52 and 5.79 mu g/mL) scavengers, as well as AChE (221.33 and 110.26 mu g/mL), BChE (461.69 and 94.93 mu g/mL), alpha-glycosidase (206.86 and 220.00 mu g/mL) and alpha-amylase (189.86 and 200.86 mu g/mL) inhibitors. As a conclusion, both EEC and WEC had rich phenolic contents and demonstrated effective anticholinergic, antidiabetic and antioxidant effects.
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    Polyphenol contents and antioxidant activity of lyophilized aqueous extract of propolis from Erzurum, Turkey
    (2010-08-01T00:00:00Z) GÜLÇİN, İlhami; Bursal, Ercan; Sehitoglu, M. Hilal; BILSEL, Mine; Goren, AHMET CEYHAN; GÖREN, AHMET CEYHAN
    Propolis, an extremely complex resinous material, exhibits valuable pharmacological and biological properties attributed to the presence of polyphenols. In this study, we determined the antioxidant properties of lyophilized aqueous extract of propolis (LAEP) from Erzurum province of Turkey and correlated the values with total levels of polyphenolic compounds. In order to estimate the capacity of LAEP to act as antioxidants, we studied its 1,1-diphenyl-2-picryl-hydrazyl radicals (DPPH center dot), 2,2--azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radicals (ABTS(center dot+)), N,N-dimethyl-p-phenylenediamine radicals (DMPD center dot+), superoxide anion radicals (O-2(center dot-)) and hydrogen peroxide (H2O2) scavenging activity, total antioxidant activity, ferric ions (Fe3+) and cupric ions (Cu2+) reducing ability, ferrous ions (Fe2+) chelating activity. LAEP inhibited 93.2% lipid peroxidation of a linoleic acid emulsion at 30 mu g/mL concentration. On the other hand, BHA, BHT, alpha-tocopherol and trolox displayed 83.3%, 82.1%, 68.1% and 81.3% inhibition of peroxidation at the same concentration, respectively. Quantitative amounts of caffeic acid, ferulic acid, syringic acid, ellagic acid, quercetin, alpha-tocopherol, pyrogallol, p-hydroxybenzoic acid, vanillin, p-coumaric acid, gallic acid and ascorbic acid were detected by high performance liquid chromatography and tandem mass spectrometry (LC-MS/MS). This study will bring an innovation for further studies with regard to the antioxidant properties of LAEP. (C) 2010 Elsevier Ltd. All rights reserved.