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GÖREN, AHMET CEYHAN

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AHMET CEYHAN
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GÖREN
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Start date: 2020 × End date: 2022 ×

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Now showing 1 - 10 of 25
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    PublicationOpen Access
    Antidiabetic, anticholinergic and antioxidant activities of aerial parts of shaggy bindweed (Convulvulus betonicifolia Miller subsp.) - profiling of phenolic compounds by LC-HRMS
    (2021-05-01T00:00:00Z) Bingol, Zeynebe; Kızıltaş, Hatice; GÖREN, AHMET CEYHAN; Kose, Leyla Polat; Topal, Meryem; DURMAZ, LOKMAN; Gulcin, İlhami; Alwasel, Saleh H.; GÖREN, AHMET CEYHAN
    In order to evaluate the antioxidant activity of evaporated ethanolic extract (EESB) and lyophilized water extract (WESB) of Shaggy bindweed (Convulvulus betonicifolia Mill. Subs), some putative antioxidant methods such as DPPH. scavenging activity, ABTS(center dot)(-) scavenging effect, ferric ions (Fe3+) reduction method, cupric ions (Cu2+) reducing capacity, and ferrous ions (Fe2+) binding activities were separately performed. Also, ascorbic acid, alpha-tocopherol and BHT were used as the standard compounds. Additionally, some phenolic compounds that responsible for antioxidant abilities of EESB and WESB were screened by liquid chromatography-high resolution mass spectrometry (LC-HRMS). At the same concentration, EESB and WESB demonstrated effective antioxidant abilities when compared to standards. In addition, EESB demonstrated IC50 values of 1.946 mu g/mL against acetylcholinesterase (AChE), 0.815 mu g/mL against alpha-glycosidase and 0.675 mu g/mL against alpha-amylase enzymes.
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    Chemical composition and biological activities of Cypriot propolis
    (2021-09-01T00:00:00Z) NALBANTSOY, AYŞE; SARIKAHYA, NAZLI; Ozverel, Cenk Serhan; Barlas, Ayse Bercin; Kirci, Damla; AKGÜN, İSMAİL HAKKI; Yalcin, Tansel; Duven, Gamze; KIŞLA, DUYGU; DEMİRCİ, BETÜL; TOPÇU, GÜLAÇTI; GÖREN, AHMET CEYHAN; TOPÇU, GÜLAÇTI; GÖREN, AHMET CEYHAN
    Propolis compositions are highly variable, depending on the geographic region and the season of collection. In this study, propolis samples from seven different regions of Cyprus were studied for the first time by means of chemical content and biological activities. Secondary metabolite composition was determined by LC-HRMS. While the major flavonoids found were isosakuranetin, naringenin, rhamnocitrin, diosmetin, chrysin and acacetin, interestingly verbascoside, a phenylethanoid glycoside, and chlorogenic acid were identified as the major compounds in the ethanol-water extracts. alpha-Pinene was detected as the major compound of propolis extracts according to the volatile compositions via GC-MS. Karaoglanoglu and Tirmen extracts, presenting different chemical profiles, exerted enormous cytotoxic activity by MTT assay (IC50: 2.36-11.56 mu g/mL; 1.44-9.33 mu g/mL, respectively). The highest iNOS inhibition potential was detected in the Karpaz extract (IC50:2.6 mu g/mL) in LPS induced RAW 264.7 cells whereas the Guzelyurt sample demonstrated remarkable antioxidant (88.82 +/- 0.10%) and antimicrobial activities (with a MIC value of 31.2 mu g/mL against S. aureus, S. epidermidis, E. faecium, and E. faecalis).
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    PublicationOpen Access
    The phenolic contents, antioxidant and anticholinesterase activity of section Amaracus (Gled.) Vogel and Anatolicon Ietsw. of Origanum L. species
    (2020-04-01T00:00:00Z) Ozer, Zuleyha; GÖREN, AHMET CEYHAN; Kilic, Turgut; Oncu, Merve; Carikci, Sema; Dirmenci, Tuncay; GÖREN, AHMET CEYHAN
    Origanum boissieri Ietsw., O. saccatum P.H.Davis, O. solymicum P.H.Davis and O. ayliniae Dirmenci & T.Yazici belonging to sect. Amaracus (Gled.) Vogel, O. sipyleum L. and O. hypericifolium O.Schwarz & P.H.Davis belonging to sect. Anatolicon Ietsw. were analyzed for their chemical composition of essential oil and phenolic components. The essential oil compositions were analysed by using GC-MS and GC-FID. The phenolic contents of the chloroform, acetone, and methanol extracts were analyzed using LC-MS/MS. Antioxidant activities of the extracts were investigated by using three methods; DPPH free radical scavenging activity, beta-carotene linoleic acid assays and CUPRAC assays. The essential oil compositions of the section Amaracus were found to be as carvacrol type (O. ayliniae, O. boissieri) and p-cymene type (O. saccatum, O. solymicum). In the section of Anatolicon, while O. sipyleum was found as gamma-terpinene type, O. hypericifolium was carvacrol type. In the extracts, the most abundant components were determined as flavonoids, coumaric acids and derivatives. Especially rosmarinic acid and penduletin were detected in high amounts. Among the studied species, extracts of O. ayliniae showed quite good activity for all methods. The extracts from all species showed remarkable antioxidant activity. Inhibition capability of the extracts against acetyl and butyrylcholinesterase enzymes (AChE and BChE) were determined. The extracts were found as inactive against AChE. The moderate inhibition capacity observed against BChE. (C) 2020 The Authors. Published by Elsevier B.V. on behalf of King Saud University.
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    Diterpenoid and phenolic contents of Sideritis hololeuca Boiss & Heldr. Apud Bentham with antioxidant and anticholinesterase activity
    (2020-05-01T00:00:00Z) Carikci, Sema; GÖREN, AHMET CEYHAN; Kilic, Turgut; GÖREN, AHMET CEYHAN
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    PublicationOpen Access
    Saponins from Twenty-Two Cephalaria Species
    (2021-11-01T00:00:00Z) Sarikahya, Nazli Boke; GÖREN, AHMET CEYHAN; Okkali, Gaye Sumer; Kirmizigul, Suheyla; GÖREN, AHMET CEYHAN
    Saponins in the Cephalaria species have a broad spectrum of biological properties and application potentials. This research aimed to develop a novel method to tentatively identify and quantify triterpenes and saponins in 22 Cephalaria species by LC-HR/MS method. In this study, we provided a broad screening of important biologically active triterpenes and saponins with high separation ability, high sensitivity and high selectivity. This is the first report to prove that Cephalaria species can be a good source of tormentic acid which has many biological activities in literature. The main triterpene compound, tormentic acid was presented at the level between 74.02 mg/kg and 75702.0 mg/kg in n-butanol extract of Cephalaria species. The source of some biologically active saponins such as davisianoside B, aristatoside C, elmalienoside A, balansoide B and scoposide B were also determined with this study, for the first time. Therefore, due to the different activities and usages of the identified compounds, these findings may find application in a number of industries such as nutraceutical, pharmaceutical, medical and cosmetic industries.
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    PublicationOpen Access
    Anticholinergic, Antidiabetic and Antioxidant Activities of Ferula orientalis L. Determination of Its Polyphenol Contents by LC-HRMS
    (2021-11-01T00:00:00Z) Kızıltaş, Hatice; GÖREN, AHMET CEYHAN; Bingol, Zeynebe; Alwasel, Saleh H.; GÜLÇİN, İlhami; GÖREN, AHMET CEYHAN
    To evaluate the antioxidant activity of evaporated ethanolic extract of Ferula orientalis L. (EEFO) and lyophilized water extract of Ferula orientalis L. (WEFO) several in vitro antioxidant methods such as ABTS(center dot+) scavenging activity, DPPH. scavenging activity, Fe(3+)reduction method, cupric ions (Cu2+) reduction capacity, and metal ion (Fe2+)-binding activities using ferrozine reagent were separately performed. Also, BHT, alpha-tocopherol and ascorbic acid were used as the standard antioxidant molecules. Moreover, some phenolic compounds that are responsible for antioxidant abilities of EEFO and WEFO were determined by LC-HRMS. EEFO and WEFO demonstrated effective antioxidant abilities when compared with the standards. EEFO demonstrated IC50 values of 1.946 mu g/mL against acetylcholinesterase (AChE), 0.815 mu g/mL against alpha-glycosidase, and 0.675 mu g/mL against alpha-amylase.
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    PublicationOpen Access
    LC-HRMS profiling of phytochemicals, antidiabetic, anticholinergic and antioxidant activities of evaporated ethanol extract of Astragalus brachycalyx Fischer
    (2021-10-01T00:00:00Z) Kızıltaş, Hatice; Bingol, Zeynebe; Goren, Ahmet C.; Pınar, Süleyman Mesut; Alwasel, Saleh H.; GÜLÇİN, İlhami; GÖREN, AHMET CEYHAN
    Astragalus is a perennial plant that has existed for about 2500-3000 years and consists of more than 250 taxonomic parts. Twenty species of Astragalus are endemic to Turkey, as well as the richest genus with 425 taxa. The roots of Asfragalus species are used in folk medicine as hepatoprotective, antioxidant, antibacterial, antihypertensive, antidiabetic and diuretic. Also, it is used to treat diabetes mellitus, leukemia, nephritis and uterine cancer. It is known that in Anatolia, Astragalus roots are traditionally used against leukemia and wound healing. For the purpose, the measuring of antioxidant activity of evaporated ethanol extract of Asfragalus brachycalyx FISCHER (EEAB), some bioanalytic methods including DPPH center dot and ABTS(center dot+) scavenging effects, ferric ions (Fe3+) and cupric ions (Cu2+) reducing abilities, and metal (Fe-) chelating activity were realized. alpha-Tocopherol, ascorbic acid, and BHT were used as the standard antioxidants. On the other hand, some phenolic compounds, which responsible for antioxidant activities of EEAB was determined by liquid chromatography-high resolution mass spectrometry (LC-HRMS). At the similar concentration, EEAB exhibited efficient antioxidant effects when compared to standard compounds. Additionally, EEAB showed IC50 values of 1.985 mu g/mL toward acetylcholinesterase (AChE), 0.620 mu g/mL on alpha-glycosidase and 0.306 mu g/mL against alpha-amylase enzymes.
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    Ent-kaurene Diterpenoids from Sideritis lycia with Antiviral and Cytotoxic Activities
    (2020-07-01T00:00:00Z) Kilic, Turgut; TOPÇU, GÜLAÇTI; GÖREN, AHMET CEYHAN; AYDOĞMUŞ, Zeynep; KARAGÖZ, Ali; Yildiz, Yasar K.; Aslan, Irfan; TOPÇU, GÜLAÇTI; GÖREN, AHMET CEYHAN
    The genus Sideritis (Lamiaceae) is represented by 45 species (54 taxa) in Anatolia with high endemism ratio (74%), and Turkey is one of the gene centers of the genus along with Spain. Acetone extract of the aerial parts of Sideritis lycia afforded eight known ent-kaurene diterpenoids, structures of which have been identified as linearol, isolinearol, isosidol, sidol, siderol, sideridiol, 7-epi-candicandiol and foliol through 1H NMR, 13 C NMR and mass spectroscopic analyses. Cytotoxic and antiviral activities of the acetone extract, linearol, sidol and isosidol were investigated together with insecticidal activity of species. The antiviral index of linearol, isosidol and acetone extract of S. lycia were determined as 2.31, 2.01 and 2.58, respectively, except sidol. 7-Epi-candicandiol was found to be the most active diterpene against a series of cancer cell lines with ED50 values; KB (13.3 mu g/mL), COL-2 (11.8 mu g/mL), LU1 (17.9 mu g/mL), LNCaP (14.9 mu g/mL) and A2780 (9.0 mu g/mL). Activity results of this study indicated that ent-kaurane diterpenes have potential to be considered as antiviral and cytotoxic lead compounds.
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    Synthesis of gamma-glutamyl beta-cyanoalanine precursor
    (2020-10-01T00:00:00Z) Un, Sule Sahin; Altundas, Ramazan; GÖREN, AHMET CEYHAN; GÖREN, AHMET CEYHAN
    The synthesis of precursors of neurotoxic gamma-glutamyl beta-cyanoalanine was developed starting from L-Serine via through the preparation of beta-cyanoalanine and glutamyl units. Coupling of these two intermediates gave methyl ester of gamma-glutamyl beta-cyanoalanine precursor. (C) 2020 ACG Publications. All rights reserved.
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    Determination of secondary metabolites of Origanum vulgare subsp. hirtum and O. vulgare subsp. vulgare by LC-MS/MS
    (2020-01-01T00:00:00Z) Ozer, Zuleyha; Carikci, Sema; Yilmaz, Hasibe; Kilic, Turgut; Dirmenci, Tuncay; GÖREN, AHMET CEYHAN; GÖREN, AHMET CEYHAN
    Secondary metabolites of solvent extracts of Origanum vulgare subsp. hirtum and O. vulgare subsp. vulgare were determined using liquid chromatography-mass spectrometry (LC-MS/MS). Curcumin was used as an internal standard. Rosmarinic acid was determined as the main compound of studied extracts together with other phenolic acid derivatives. In LC-MS/MS analyses, relative standard deviations (RSD %) ranged between 0.11-9.47. The correlation values were found to be greater than 0.97 for each investigated analyte.