Person: DOĞAN, AHMET
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DOĞAN
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AHMET
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Publication Metadata only HPLC-MS/MS-based metabolic profiling and pharmacological properties of extracts and infusion obtained from Amelanchier parviflora var. dentata(ELSEVIER SCIENCE BV, 2018) DOĞAN, AHMET; Zengin, Gokhan; Diuzheva, Alina; Jeko, Jozsef; Cziaky, Zoltan; Bulut, Gizem; Dogan, Ahmet; Haznedaroglu, Mehmet Zeki; Rengasamy, Kannan R. R.; Lobine, Devina; Bahadori, Mir Babak; Mahomoodally, Mohamad FawziArnelanchierparviflora var. dentata is an endemic medicinal plant traditionally consumed to treat stomach pain, cardiovascular diseases, and urinary tract infections in Turkey's folk medicine. Although Amelanchier genus is an excellent source of phytochemicals with a panoply of biological activities, no report has been made available on Amelanchier parviflora var. dentata. Thus, the metabolic profiles of methanol, ethyl acetate, and water extracts were obtained using HPLC-MS/MS. Besides, the pharmacological properties such as antioxidant activity and enzyme inhibition effects against acetyl/butyrylcholinesterase, tyrosinase, alpha-amylase, and alpha-glucosidase were evaluated. In total, 62, 38, and 16 metabolites were Identified from the methanolic, water, and ethyl acetate extracts, respectively. The identified metabolites belong to anthocyanins, phenolic acids, and flavonoids. The tested extracts exhibited different enzyme inhibitory activity against cholinesterases (acetylcholinesterase: 0.52-2.47 mg GEs/g extract and butyrylcholinesterase: 0.47-3.59 mg GEs/g extract), tyrosinase (19,0-145.54 mg KAEs/g extract), alpha-amylase (0.23-1.10 mmol ACEs/g extract), and alpha-glucosidase (8.89-9.92 mmol ACEs/ g extract). Evidence from the present study supports the necessity for more research in an endeavor to discover biologically active secondary metabolites from A. parviflora to manage specific ailments.Publication Metadata only Characterization of Phenolic Constituents and Pharmacological Activity of Achillea vermicularis(INDIAN PHARMACEUTICAL ASSOC, 2019) DOĞAN, AHMET; Taskin, T.; Balkan, I. E.; Tankin, D.; Dogan, A.The aim of the present study was to compare for the first time, the antiinflammatory, antioxidant and antiurease activities of 15 different extracts of Achillea vermicularis, which were obtained from three extraction methods using five different solvents. Phenolic contents in chloroform extract showed strong antiinflammatory and antioxidant activity and were analysed by high-performance liquid chromatography with diode-array detection and confirmed by liquid chromatography quadrupole time-of-flight mass spectrometry. The active phenolic compounds in chloroform extracts were identified as chlorogenic acid, caffeic acid, rutin, dicaffeoylquinic acid, naringenin, quercetagetin 3,6-dimethyl ether, and 8-hydroxysalvigenin. All these compounds except caffeic acid were detected for the first time in Achillea vermicularis. These results indicated that chloroform extract of the plant possessed a high potential to be used as a natural source in food and pharmaceutical industry.Publication Open Access In vitro biological activities of different extracts from alcea dissecta(2022-03-01) TAŞKIN, TURGUT; DOĞAN, AHMET; TAŞKIN T., Kahvecioglu D., Turkoglu E. A., DOĞAN A., Kuzu M.Objective: Alcea genus belongs to Malvaceae family and this genus is represented by 85 taxa in the world and 21 taxa in the Flora of Turkey. The flowers of Alcea genus contain plenty of mucilage and are used for the treatment of respiratory diseases such as asthma and cough. Alcea dissecta is known as ‘Govik, Hiro, Hero’ in Turkey, and the flowers and leaves of this species have been used in the treatment of asthma, injury, colds, and gastrointestinal diseases in Turkey. To the best of our knowledge, there is no report on the effect of extraction methods on the biological activity of this plant. In addition, although this species is being used as a medical plant, there is no study of the antioxidant, antiurease, esterase, and anticholinesterase activity of the plant. Therefore, the aim of this study was to evaluate in vitro antioxidant, anti-urease, esterase, anticholinesterase activities of Alcea dissecta using a variety of extracts. Methods: The antioxidant activities of different extracts were examined by DPPH, ABTS, FRAP, and CUPRAC methods. The total phenolic compounds contained in the extracts were determined using the Folin-Ciocalteu reagent (FCR) method. Anti-urease and anticholinesterase activities of different extracts were evaluated by indophenol and Ellman methods respectively. In addition, esterase activities of plant extracts were determined. Results: In the present study, ethanol:water (1:1, v/v) and chloroform extracts obtained maceration method showed stronger DPPH and ABTS radical scavenging activity than other extracts. The chloroform extract obtained Soxhlet method was found to have higher FRAP and CUPRAC values than other extracts. It was also found that the ethanol extract obtained maceration method showed the most potent anti-urease and anticholinesterase activity. According to the results, the strongest inhibitory effect on both hCA I and II isoenzymes was shown by the petroleum ether extract obtained Soxhlet method. Conclusion: As a result, it was determined that different plant extracts have antioxidant, anti-urease, esterase, anticholinesterase activities. In addition, the data obtained from this study will shed light on future research on the biological activities of this species.Publication Metadata only New insights into the in vitro biological effects, in silico docking and chemical profile of clary sage - Salvia sclarea L.(ELSEVIER SCI LTD, 2018) DOĞAN, AHMET; Zengin, Gokhan; Senkardes, Ismail; Mollica, Adriano; Picot-Allain, Carene Marie Nancy; Bulut, Gizem; Dogan, Ahmet; Mahomoodally, M. FawziSalvia sclarea L. is traditionally used to manage common human ailments and is consumed as a food product. This study aimed to establish the phytochemical profile and antioxidant potential of ethyl acetate, methanol, and water extracts of Salvia sclarea. The inhibitory action of the extracts against alpha-amylase, alpha-glucosidase, acetyicholinesterase, butyrylcholinesterase, and tyrosinase was also investigated. Methanol extract showed the highest phenolic and fiavonoid contents (81.78 mg GAE/g extract and 40.59 mg RE/g extract, respectively). Reversed phase high performance liquid chromatography with diode array detector analysis revealed that S. sclarea was rich in rosmarinic acid. The water extract exhibited the lowest inhibitory activity against alpha-amylase but the upmost activity against alpha-glucosidase (0.19 and 18.24 mmol ACAE/g extract, respectively). Experimental data showed that only the water extract (8.86 mg KAE/g extract) significantly inhibited tyrosinase. Docking studies showed that quercetin binds to tyrosinase by two hydrogen and a pi-pi bonds. Salvia sclarea showed interesting biological activity against key enzymes involved in the pathogenesis of common ailments. (C) 2018 Elsevier Ltd. All rights reserved.Publication Metadata only Biologically active compounds from two members of the Asteraceae family: Tragopogon dubius Scop. and Tussilago farfara L.(TAYLOR & FRANCIS INC, 2019) DOĞAN, AHMET; Uysal, Sengul; Senkardes, Ismail; Mollica, Adriano; Zengin, Gokhan; Bulut, Gizem; Dogan, Ahmet; Glamoclija, Jasmina; Sokovic, Marina; Lobine, Devina; Mahomoodally, Fawzi M.Tragopogon dubius and Tussilago farfara are consumed as vegetables and used in folk medicine to manage common diseases. Herein, the chemical compositions and biological activities of different leaf extracts (ethyl acetate, methanol, and water) of T. dubius and T. farfara were evaluated. The antibacterial, antifungal, and antioxidant abilities of the extracts were tested using different assays including free radical scavenging, reducing power, phosphomolybdenum, and metal chelating assays. Enzyme inhibitory potentials were evaluated against cholinesterases, tyrosinase, alpha-amylase and alpha-glucosidase. Complexes of bioactive compounds (chlorogenic and rosmarinic acid) were docked into the enzymatic cavity of alpha-glucosidase and subjected to molecular dynamic calculation, enzyme conformational stability, and flexibility analysis. T. dubius and T. farfara extracts showed remarkable antioxidant potentials. Ethyl acetate extracts of T. dubius and T. farfara were the most potent inhibitors of acetylcholinesterase and butyrylcholinesterase. T. dubius ethyl acetate extract and T. farfara methanolic extract showed noteworthy activity against alpha-glucosidase. High performance liquid chromatography analysis revealed the abundance of some phenolic compounds including chlorogenic and rosmarinic acids. Ethyl acetate extract of T. dubius showed notable antifungal activity against all strains. Docking studies showed best pose for chlorogenic acid was stabilized by a network of hydrogen bonds with residues Asp1157, Asp1279, whereas rosmarinic acid showed several hydrogen bonds with Asp1157, Asp1420, Asp1526, Lys1460 and Trp1369. This study further validates the use of T. dubius and T. farfara in traditional medicine, as well as act as a stimulus for further studies for future biomedicine development. Communicated by Ramaswamy H. SarmaPublication Metadata only Chemical composition and biological activities of endemicTripleurospermum conoclinium(Boiss. & Balansa) Hayek essential oils(WILEY, 2020) DOĞAN, AHMET; Servi, Huseyin; Sen, Ali; Dogan, AhmetThe volatile oils of flowers (TFE), leaves (TLE) and stems (TSE) ofTripleurospermum conoclinium(Boiss. & Balansa) Hayek were obtained by hydrodistillation method for 3 hours with Clevenger-type apparatus. Chemical composition of oils was determined by GC-MS analyses. Antidiabetic, anti-inflammatory and antioxidant activities of oils were tested by alpha-glucosidase inhibitory, 5-lipoxygenase inhibitory and DPPH/ABTS radical scavenging methods, respectively. Eighty-five constituents were identified in flower oil (78.3%). The major compounds of flower oil were artemisia ketone (10.5%), beta-oplopenone (6.0%), tricosane (4.5%), terpinen-4-ol (3.7%) and artemisia alcohol (3.5%). Sixty-two constituents were identified in leaf oil (67.0%). 1-octadecanol (11.5%), caryophyllene oxide (5.7%), elemol (3.9%), phytol (3.5%), ledene oxide (3.3%) and artemisia ketone (3.1%) were found as main constituents in the leaf oil. Forty-six constituents were determined in the stem oil (75.1%). The main compounds of the stem oil were 1-octadecanol (11.1%), beta-oplopenone (5.5%), ledene oxide (5.5%), caryophyllene oxide (4.4%) and phytol (3.0%). TLE and TSE displayed strong antidiabetic activity with IC(50)values of 21.30 and 29.57 mu g/mL against alpha-glucosidase enzyme, respectively. TLE showed the best anti-inflammatory activity with an IC(50)value of 91.02 mu g/mL while TFE and TSE exhibited moderate activity with IC(50)values of 186.50 and 257.10 mu g/mL, respectively. TFE and TLE were found to possess moderate antioxidant activity with IC(50)values of 572.80 and 385.80 mu g/mL against ABTS radical while all essential oils showed weak activity against DPPH radical. To the best of our knowledge, this is first report on chemical composition and biological activities ofTconocliniumessential oils.Publication Open Access Chemical composition and biological activities of essential oils of Foeniculum vulgare Mill. and Daucus carota L. growing wild in Turkey(MARMARA UNIV, 2021) DOĞAN, AHMET; Servi, Huseyin; Sen, Ali; Servi, Esra Yildirim; Dogan, AhmetThe chemical composition of essential oils of aerial parts of Daucus carota (DEO) and Foeniculum vulgare (FEO) was specified by GC/MS. Antidiabetic, anti-inflammatory, antioxidant, and antibacterial activities of oils were tested by alpha-glucosidase inhibitory, 5-lipoxygenase inhibitory, DPPH/ ABTS radical scavenging, and broth microdilution methods, respectively. Thirty components were identified in DEO (87.7%). Carotol (27.7%), elemicin (18.1%), and limonene (16.0%) were determined as the main compounds in DEO. Seventeen constituents were identified in FEO (100.0%). Estragole (34.0%), limonene (27.1%), and alpha-pinene (19.5%) were found as major components in FEO. Both oils displayed weak antibacterial activity against Gram-negative bacteria. However, the oils were not effective on Grampositive bacteria. DEO with IC50 values of 1359 and 1579 mu g/mL and FEO with IC50 values of 3106 and 1654 mu g/mL showed weak antioxidant activities against DPPH and ABTS radicals, respectively. DEO and FEO exhibited good antilipoxygenase activities with IC50 values of 87.24 and 58.35 mu g/mL, respectively. DEO presented significantly alpha-glucosidase inhibitory activity with an IC50 value of 44.78 mu g/mL while FEO displayed poor activity with an IC50 value of 1%7 mu g/mL. This study is the first report on the 5-lipoxygenase and alpha-glucosidase inhibitory activities of aerial parts of DEO as well as on the alpha-glucosidase inhibitory activity of aerial parts of FEO. These results indicated that DEO, which has a good antidiabetic and anti-inflammatory activity, is rich in oxygenated sesquiterpene and monoterpene. Also, it showed that FEO, which has a significant anti-inflammatory activity, is rich in monoterpene and phenylpropanoid.Publication Open Access Bioactivities of Achillea phrygia and Bupleurum croceum based on the composition of phenolic compounds: In vitro and in silico approaches(2017-09-01) EMRE, GİZEM; DOĞAN, AHMET; Zengin G., EMRE G., Mollica A., Haznedaroglu M. Z. , DOĞAN A., Aktumsek A.This study presents the effects of the Achillea phrygia Boiss. et Bal. and Bupleurum croceum Fenzl. extracts obtained by different solvents (ethyl acetate, methanol and water) on selected enzyme inhibitory effects and antioxidant ability with screening bioactive compounds. Total and individual bioactive compounds were detected by spectrophotometric and HPLC-DAD techniques. Antioxidant abilities were evaluated by different methods including free radical scavenging (ABTS and DPPH), reducing power (CUPRAC and FRAP), phosphomolybdenum and metal chelating. Enzyme inhibitory effects were tested against cholinesterases, tyrosinase, amylase, glucosidase and lipase. Total phenolic contents were ranged from 20.52 mgGAE/g extract (B. croceum methanol extract) to 41.13 mgGAE/g extract (A. phrygia methanol extract). Generally, methanol and water extracts showed the strongest antioxidant abilities, while the ethyl acetate extracts had the most promising enzyme inhibitory effects. HPLC analysis revealed the abundance of some phenolics including rutin, quercetin, sinapic acid and chlorogenic acid, respectively. These components were also assessed using molecular modelling with the aim to study their docking properties on a set of six enzymes used in this study. Overall, these species could be suggested as valuable sources of natural-bioactive agents for developing new functional, pharmacological and health promoting ingredients. (C) 2017 Elsevier Ltd. All rights reserved.