Person: DOĞAN, AHMET
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DOĞAN
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AHMET
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Publication Metadata only Phenolic components and assessment of biological properties of Tchihatchewia isatidea Boiss. extracts: Docking and functional approaches for designing novel products(PERGAMON-ELSEVIER SCIENCE LTD, 2018) DOĞAN, AHMET; Zengin, Gokhan; Abdallah, Hassan H.; Dogan, Ahmet; Mollica, Adriano; Aumeeruddy-Elalfi, Zaahira; Mahomoodally, Mohamad FawziThe potentiality of bioactive phenolic compounds may result in plant extracts having multiple biological activities. The aim of this study was to investigate into the biological activities of the methanolic, ethyl acetate, and water extracts of Tchihatchewia isatidea Boiss, an endemic medicinal plant of Turkey. The phenolic compositions of the extracts were confirmed using RP-HPLC. Extracts were screened for their potential antioxidant through a panoply of assays; their anti-diabetic potential, and plausible inhibitory activity against tyrosinase and acetylcholinesterase. Molecular modelling methods were also used to assess the docking properties of phenolic compounds on tyrosinase. The major and most abundant compounds were rosmarinic acid (570 +/- 14 mu g/g extract in the methanolic extract), ferrulic acid (336 +/- 6 mu g/g extract in the methanolic extract), (+)-catechin (340 +/- 4 mu g/g extract in the water extract), apigenin (182 +/- 4 mu g/g extract in the methanolic extract), and epicatechin (188 12 g/g extract in the water extract). Radical scavenging, reducing capacity, and metal chelating activities were detected in the extracts, with preponderance activity observed in the methanolic extract. In conclusion, the potential clinical applications observed during this study may provide new insights into the molecular aspect particularly for neuroprotective and anti-diabetic mechanisms involving oxidative stress.Publication Metadata only Chemical composition and bio-functional perspectives of Erica arborea L. extracts obtained by different extraction techniques: Innovative insights(ELSEVIER, 2019) DOĞAN, AHMET; Zengin, Gokhan; Cvetanovic, Aleksandra; Gasic, Uros; Stupar, Alena; Bulut, Gizem; Senkardes, Ismail; Dogan, Ahmet; Seebaluck-Sandoram, Roumita; Rengasamy, Kannan R. R.; Sinan, Kouadio Ibrahime; Mahomoodally, Mohamad FawziErica arborea L., also known as Estrella Gold, is traditionally used for several purposes. In this research, five different extraction techniques: accelerated solvent extraction (ASE), microwave-assisted extraction (MAE), maceration (MAC), soxhlet (SOE) and ultrasound-assisted extraction (UAE) were used to compare the total phenolic, flavonoids, total antioxidant activity and enzymatic activities of E. arborea extracts obtained different extraction techniques. The total phenolic and flavonoid contents were in the order of ASE > MAE > SOE > MAC > UAE. All extracts showed antioxidant, anticholinesterase, anti-tyrosinase and anti-diabetic activities. A highly sensitive method using ultra-high-pressure liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap-MS) has been used for the qualitative analysis of obtained extracts. Seventy-two polyphenolic compounds were identified in all extracts. However, 20 components were quantified among the extracts. ASE was found to be a better extraction technique as compared to the other extraction techniques. E. arborea can be exploited in the discovery of bioactive natural products for the treatment of Alzheimer's disease, diabetes and pigmentation problems.Publication Metadata only Chemical composition of endemic Stachys subnuda Montbret & Aucher ex Benth. essential oil and its anti-inflammatory and antioxidant activities(TAYLOR & FRANCIS INC, 2019) DOĞAN, AHMET; Sen, Ali; Kurkcuoglu, Mine; Bitis, Leyla; Dogan, Ahmet; Baser, Kemal Husnu CanThe essential oil of aerial parts of Stachys subnuda Montbret & Aucher ex Benth (S. subnuda) was analyzed by gas chromatography (GC) and GC/mass spectrometry (MS). Anti-inflammatory activity was evaluated by lipoxygenase inhibition assay. The antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-3-ethylbenzothiozoline-6-sulfonic acid (ABTS) assays. Sixty-two constituents, comprising 97.1% of the total essential oil composition, were identified. Phytol (25.2%), beta-caryophyllene (11.2%), germacrene D (6.9%), and hexadecanoic acid (6.9%) were the major compounds of aerial part essential oils of S. subnuda. The essential oil showed significant radical scavenging activity with 50% inhibition (IC50) values of 0.124 and 0.204 mg/mL for ABTS and DPPH radicals, respectively. The essential oil exhibited moderate anti-inflammatory activity with an IC50 value of 0.419 mg/mL. The results indicated that S. subnuda essential oil had good anti-inflammatory and antioxidant activity. Also, this is first study on chemical composition, anti-inflammatory and antioxidant activity of S. subnuda essential oil.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 Metadata only Turkish folk medicinal plants, IX: Ovacik (Tunceli) [Türkiye'nin halk ilacı bitkileri, IX: Ovacık (Tunceli)](Marmara University, 2010) DOĞAN, AHMET; Tuzlaci E., Doǧan A.The aim of this study was made to reveal the plants used as traditional folk medicine in Ovaci{dotless}k (Tunceli). For this purpose, the field works have been done between May 2007-May 2008 in April, May, June and July lasting for 30 days, in total. During this research all the settlement centers (including 33 villages) have been visited, the specimens of the plants used as folk remedies have been collected and the information such as local names, ailments treated or therapeutic effects, plant parts used, method of administration, dosage, duration of treatment have been recorded. The collected plant specimens are kept in the Herbarium of the Faculty of Pharmacy, Marmara University (MARE). As a result of identification of 76 plant specimens, 67 species used as a traditional folk medicine, have been determined. Among them 65 species are wild and 2 species are cultivated plants. These plants and their local usage in treatment are presented in a table in the text. It was found out that the plants recorded in Ovaci{dotless}k are mostly used for cold, diabetes and wound.Publication Open Access An Ethnobotanical study of medicinal plants in Taşköprü (Kastamonu–Turkey)(2022-10-20) ŞENKARDEŞ, İSMAİL; DOĞAN, AHMET; EMRE, GİZEM; ŞENKARDEŞ İ., DOĞAN A., EMRE G.Copyright © 2022 Senkardes, Dogan and Emre.This pharmaceutical ethnobotanical research was carried out in Taşköprü District in Kastamonu, in northern Anatolia. It assembles the elaborations of plants used as folk medicines, and the ethnopharmacological data collected in the course of in-person semi-structured interviews with an open-ended questionnaire. The study’s aims were two-fold: gathering and identifying plants that the local inhabitants use therapeutically, and recording information related to traditional folk medicine (primarily for humans, and if extant for animals). The plants were gathered during several outings between May 2016 and July 2018. The organization of the data was based on the use-reports (UR) and was done according to the ICPC-2 classification. In addition, cultural importance index (CI) and informant consensus factor (FIC) calculations were made for the data collected. The research identified 101 plant taxa of 31 families used in folk medicine. Of these, 89 were wild and 12 were cultivated taxa. In total, 499 medicinal uses were determined. The CI values indicated that the most significant medicinal plant specimens were Pinus nigra subsp. pallasiana (0.78), P. sylvestris var. hamata (0.75) and Plantago lanceolata, P. major subsp. intermedia and P. major subsp. major (0.58 each). The most prevalent families were Asteraceae (2.14), Rosaceae (1.93), Pinaceae (1.81) and Plantaginaceae (1.74). Respiratory system (0.95), skin and subcutaneous tissue (0.94), nervous system (0.92) and circulatory system disorders (0.88) and ethnoveterinary uses (0.89) had the highest FIC values. The most frequently used preparation process was observed to be decoction (38.4%) and the most commonly utilized plant parts were aerial (21%). Along with recording 20 plant taxa as medicinal plants for the first time, this study documented a total of 303 new therapeutic uses. This study concludes with the finding that traditional knowledge of medicinal plants remains prevalent in Ta rticularly among its rural inhabitants.Publication Open Access Two Acylated Isoscutellarein Glucosides with Anti-Inflammatory and Antioxidant Activities Isolated from Endemic Stachys Subnuda Montbret & Aucher ex Benth(SLOVENSKO KEMIJSKO DRUSTVO, 2019-12-18) DOĞAN, AHMET; Sen, Ali; Goger, Fatih; Dogan, Ahmet; Bitis, LeylaIn this study, we report anti-inflammatory and antioxidant activities of two acylated isoscutellarein glucosides isolated from ethyl acetate extract of Stachys subnuda aerial part. 4'-O-methylisoscutellarein-7-O-2 ''-O-(6 ''' acetyl-beta-D-allopyranosyl)-beta-D-glucopyranoside (SS1) and isoscutellarein-7-O-2 ''-O-(6 '''-O-acetyl-beta-D allopyranosyl)-beta-D -glucopyranoside (SS2) were isolated as major compounds from ethyl acetate extract (SSEA). Also, 2 hydroxycinnamic acid derivatives, and 5 isoscutellarein glucoside derivatives in the SSEA were identified using LC-MS/MS. SS1 with IC50 values of 2.35 and 1.98 mu g/mL and SS2 with IC50 values 13.94 and 12.76 mu g/mL showed fairly strong antioxidant activity against DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid) radicals, respectively. SS1 and SS2 inhibited 5-lipoxygenase (5-LOX) activity with IC(50 )values of 47.23 and 41.60 mu g/mL, respectively. The results demonstrated that SS1 and SS2 have significant anti-inflammatory and antioxidant potential. Acylated flavonoid glycosides have been first reported for Stachys subnuda. Also, the activities of SS1 and SS2 have been investigated for the first time in this study.Publication Metadata only Essential oil composition of different parts of Tanacetum cilicicum (Boiss.) Grierson(Badebio Biotechnololgy Ltd, 2020) DOĞAN, AHMET; Şen A., Kürkçüoğlu M., Bitiş L., Doğan A., Başer K.H.C.The aim of this study was to investigate and compare the chemical composition of essential oils obtained by Clevenger-type apparatus from capitula (TCC) and aerial parts including leaves and stems (TCA) of Tanacetum cilicicum (Boiss.) Grierson from Turkey. TCC and TCA essential oils were separately analysed by GC-FID and GC/MS. Forty and thirty-two compounds were identified, representing 99% and 94.4% of the oils of TCC and TCA essential oils, respectively. The main constituents of the oil of the TCC were camphor (28.8%), (E)-nerolidol (16.9%), trans-chrysanthenyl acetate (12.8%) and 1,8-cineole (8.9%), whereas the oil from TCA comprised mainly trans-chrysanthenyl acetate (22.2%), borneol (19.4%), camphor (11.2%), 1,8-cineole (10.2%) and (E)-nerolidol (9.2%). The results showed that TCC and TCA essential oils were rich in oxygenated monoterpenes and oxygenated sesquiterpenes. This study is the first to study the essential oil composition of different parts of Tanacetum cilicicum separately. Also, to the our best of our knowledge, (E)-nerolidol was found in the Tanacetum species as the major compound for the first time. © 2020, Badebio Biotechnololgy Ltd. All rights reserved.Publication Metadata only Anti-quorum sensing and anti-biofilm activities of Hypericum perforatum extracts against Pseudomonas aeruginosa(ELSEVIER IRELAND LTD, 2019) DOĞAN, AHMET; Dogan, Sule; Gokalsin, Baris; Senkardes, Ismail; Dogan, Ahmet; Sesal, N. CenkEthnopharmacological relevance: Hypericum perforatum L. (Hypericaceae) has been used as a traditional therapeutic for skin wounds, burns, cuts and stomach ailments including stomach ache, ulcers for a long time in many societies. Although many studies about its antibacterial properties can be found, there is a lack of studies about its quorum sensing inhibition properties, which effects bacterial vulnerability directly, on Pseudomonas aeruginosa. Aim of the study: Evaluation of anti-quorum sensing (anti-QS) and anti-biofilm activity of ethanol, methanol, acetone and ultra-sonicated extracts of Hypericum perforatum L. (HP) which is a well-known wound healer, against P. aeruginosa. Materials and methods: Aerial parts of HP were extracted with ethanol, methanol and acetone. In addition, separate extractions with ultrasonication were carried out with same solvents. Anti-QS activity tests with different doses of HP extracts were performed by employing biomonitor strains, of which the promoter of QS regulating and green fluorescent protein (GFP) genes were fusioned. For anti-biofilm activity, HP extracts were applied to wild type PAO1 strains and biofilm inhibition was quantified via crystal violet staining method. Results: HP's ethanol, methanol and acetone extracts (250 mu g/ml doses) inhibited LasIR signalling pathway up to 65.43%, 59.60%, 55.95% and same solvent extracts obtained with ultrasonication inhibited 71.33%, 64.47%, 57.35% respectively. Moreover, inhibition rates of Rh1IR pathway were 28.80%, 50.83%, 45.84% for ethanol, methanol, acetone extracts (250 mu g/ml doses) and 51.43%, 57.41%, 50.02% for ultrasonication extracts (250 mu g/ml doses), compared to untreated controls. In the experiments, ethanol, methanol, acetone and ultra-sonicated extracts of HP did not inhibit biofilm formation. Conclusions: This study shows that HP plant is capable for blocking of las and rhl QS systems of P. aeruginosa. However, it was observed that ethanol, methanol and acetone extract of the plant samples did not show anti-biofilm activity against P. aeruginosa. This led us to thinking that biofilm formation was caused via another pathway such as IQS or PQS. Further studies with isolated active compounds of HP might give a better understanding of the effects on biofilm formation of P. aeruginosa.
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