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Öğe 4-(3-Nitrophenyl)thiazol-2-ylhydrazone derivatives as antioxidants and selective hMAO-B inhibitors: synthesis, biological activity and computational analysis(TAYLOR & FRANCIS LTD, 2019) Secci, Daniela; Carradori, Simone; Petzer, Anel; Guglielmi, Paolo; D'Ascenzio, Melissa; Chimenti, Paola; Bagetta, Donatella; Alcaro, Stefano; Zengin, Gökhan; Petzer, Jacobus P.; Ortuso, FrancescoA new series of 4-(3-nitrophenyl)thiazol-2-ylhydrazone derivatives were designed, synthesised, and evaluated to assess their inhibitory effect on the human monoamine oxidase (hMAO) A and B isoforms. Different (un)substituted (hetero)aromatic substituents were linked to N1 of the hydrazone in order to establish robust structure-activity relationships. The results of the biological testing demonstrated that the presence of the hydrazothiazole nucleus bearing at C4 a phenyl ring functionalised at the meta position with a nitro group represents an important pharmacophoric feature to obtain selective and reversible human MAO-B inhibition for the treatment of neurodegenerative disorders. In addition, the most potent and selective MAO-B inhibitors were evaluated in silico as potential cholinesterase (AChE/BuChE) inhibitors and in vitro for antioxidant activities. The results obtained from molecular modelling studies provided insight into the multiple interactions and structural requirements for the reported MAO inhibitory properties.Öğe Acanthus Hirsutus‘un Aseton Özütünün Anti?oksi?dan Özelli?kleri?ni?n Araştırılması(Selçuk Üniversitesi Fen Fakültesi, 2014) Güner, Sevilay; Zengin, Gökhan; Aktümsek, AbdurrahmanAcanthus hirsutus Anadolu geleneksel halk hekimliğinde çeşitli hastalıkların tedavisinde kullanılmaktadır. Bu çalışmada A. hirsutus’un aseton ekstraktının antioksidan özellikleri; toplam antioksidan, serbest radikal süpürme etkinliği (DPPH testi), ?-karoten/linoleik asit metodu, demir ve bakır indirgeme güçlerini içeren farklı kimyasal test sistemleri kullanılarak değerlendirilmiştir. Toplam fenolik ve flavonoid içerikler belirlenmiştir. Toplam fenolik ve flavonoid içerik sırasıyla 51.39 mgGAE/g ve 18.60 mgRE/g olarak tespit edilmiştir. DPPH yönteminde 1mg/ml konsantrasyonda %47.87 etkinlik gözlenmiştir. ?-karoten/linoleik asit test sisteminde, 1 mg/ml konsantrasyon linoleik asit oksidasyonu %66.83 oranında inhibe edilmiştir. Demir ve bakır indirgeme güçleri ise konsantrasyona bağlı bir durum sergilemektedir. Bu sonuçlar A. hirsutus’un doğal antioksidanların bir kaynağı olarak gıda ve farmakoloji endüstrilerinde kullanılabileceğini göstermektedir.Öğe Ajuga chamaecistus subsp scoparia (Boiss.) Rech.f.: A new source of phytochemicals for antidiabetic, skin-care, and neuroprotective uses(ELSEVIER SCIENCE BV, 2016) Movahhedin, Nasrin; Zengin, Gökhan; Bahadori, Mir Babak; Sarıkürkcü, Cengiz; Bahadori, Shahram; Dinparast, LeilaThe genus Ajuga is used traditionally as food and medicine. The aim of this study was to investigate the antidiabetic, anti-Alzheimer's diseases, skin-protective, and antioxidant activities of essential oil and extracts of Ajuga chamaecistus subsp. scoparia (Boiss.) Rech.f., together with the identification of their chemical composition. The 1,1-dipheny1-2-picrylhydrazyl radical and 2,2-azino-bis (3-ethylbenzothiazloine-6-sulfonic acid) radical cation scavenging activity, metal chelating activity, reducing power, content of total bioactive compounds, general toxicity, and enzyme inhibitory potential of essential oil, ethanol extract, and water decoction of the plant were evaluated. Phenolics profile of the extracts was analyzed using the reverse-phase high-performance liquid chromatography with diode array detector and the chemical composition of the essential oil was determined using the gas chromatography and gas chromatography mass spectroscopy techniques. The essential oil could significantly inhibit the activity of alpha-glucosidase (4.3 mmol Acarbose equivalents/g), alpha-amylase (2.8 mmol Acarbose equivalents/g), acetylcholinesterase (1.96 mg gallic acid equivalents/g), butyrylcholinesterase (2.2 mg gallic acid equivalents/g), and tyrosinase (36 mg kojic acid equivalents/g) while ethanol and water extracts showed moderate enzyme inhibitory activity. Furthermore, essential oil had the strongest antioxidant capacity in the 1,1-diphenyl-2-picrylhydrazyl scavenging, 2,2-azino-bis (3ethylbenzothiazloine-6-sulfonic acid) scavenging, cupric reducing antioxidant capacity, ferric reducing antioxidant power, and metal chelating assays. Spathulenol (18.0%), thymol (15.1%), octen-3-ol (14.3%), and linalool oxide (11.2%) were identified as major constituents in the essential oil. Quantitative highperformance liquid chromatography analysis indicated that p-coumaric acid, gallic acid, and ferulic acid are the main phenolic compounds in this plant. The results suggested that Ajuga chamaecistus could be useful for several applications as functional foods, cosmetics, and pharmaceuticals. (C) 2016 Elsevier B.V. All rights reserved.Öğe Alchemilla vulgaris agg. (Lady's mantle) from central Balkan: antioxidant, anticancer and enzyme inhibition properties(ROYAL SOC CHEMISTRY, 2019) Vlaisavljevic, Sanja; Jelaca, Sanja; Zengin, Gökhan; Mimica-Dukic, Neda; Berezni, Sanja; Miljic, Milorad; Stevanovic, Zora DajicThe current study was designed to evaluate the phytochemical profile and biological properties (antioxidant, enzyme inhibitory and cytotoxic activity) of methanolic, ethanolic, ethyl-acetate and water extracts of Alchemilla vulgaris from Southeast Serbia (central Balkan) which was traditionally used to alleviate and treat many diseases. Bioactive compounds were characterized by LC-MS/MS technique and biological properties were evaluated using antioxidant, enzyme inhibitory and cytotoxic assays. Twenty-six phenolic compounds were quantified in methanolic, ethanolic, ethyl acetate and water extracts, whereas the highest yields were found in ethyl-acetate (EA) extract (gallic acid, caffeic acid, catchin, quercetin). This extract has also shown the greatest antioxidant, anticancer and inhibitory enzyme activities which were demonstrated for the first time in this study. The obtained results indicated that Alchemilla vulgaris from South Serbia possesses high potential for pharmaceutical applications.Öğe Anthraquinone profile, antioxidant and enzyme inhibitory effect of root extracts of eight Asphodeline taxa from Turkey: can Asphodeline roots be considered as a new source of natural compounds?(TAYLOR & FRANCIS LTD, 2016) Zengin, Gökhan; Locatelli, Marcello; Ceylan, Ramazan; Aktümsek, AbdurrahmanPlant-based foods have become attractive for scientists and food producers. Beneficial effects related to their consumption as dietary supplements are due to the presence of natural occurring secondary metabolites. In this context, studies on these products are important for natural and safely food ingredients evaluation. The aim of this study was to evaluate root extract of eight Asphodeline species as antioxidants, enzyme inhibitors and phytochemical content. Spectrophotometric antioxidant and enzyme inhibitory assays were performed. Total phenolic and flavonoids contents as well as the chemical free-anthraquinones profiles were determined using routinely procedure (HPLC-PDA). Data show that Asphodeline roots can be considered as a new source of natural compounds and can be used as a valuable dietary supplement. Some differences related to biological activities can be inferred to other phytochemicals that can be considered in the future for their synergic or competitive activities.Öğe Anti-oxidant and tyrosinase inhibitory in vitro activity of amino acids and small peptides: new hints for the multifaceted treatment of neurologic and metabolic disfunctions(MDPI, 2019) Luisi, Grazia; Stefanucci, Azzurra; Zengin, Gökhan; Dimmito, Marilisa Pia; Mollica, AdrianoOxidative damage is among the factors associated with the onset of chronic pathologies, such as neurodegenerative and metabolic diseases. Several classes of anti-oxidant compounds have been suggested as having a protective role against cellular stressors, but, in this perspective, peptides' world represents a poorly explored source. In the present study, the free radical scavenging properties, the metal ion reducing power, and the metal chelating activity of a series of sulfurated amino acids and tripeptides were determined in vitro through canonical assays (DPPH, ABTS, CUPRAC, FRAP, PM, and EECC) and estimated in comparison with the corresponding activities of synthetic peptide semicarbazones, incorporating the peculiar non-proteinogenic amino acid, tert-leucine (tLeu). The compounds exhibited remarkable anti-oxidant properties. As expected, sulfurated compounds 1-5 were found to be the most efficient radical scavengers and strongest reductants. Nevertheless, tLeu-containing peptides 7 and 8 disclosed notable metal reducing and chelating activities. These unprecedented results indicate that tLeu-featuring di- and tripeptide backbones, bearing the semicarbazone chelating moiety, are compatible with the emergence of an anti-oxidant potential. Additionally, when tested against a panel of enzymes usually targeted for therapeutic purposes in neurodegenerative and metabolic disorders, all samples were found to be good inhibitors of tyrosinase.Öğe Antibacterial activities of extracts from twelve centaurea species from Turkey(INST BIOLOSKA ISTRAZIVANJA SINISA STANKOVIC, 2011) Tekeli, Yener; Zengin, Gökhan; Aktümsek, Abdurrahman; Sezgin, Mehmet; Torlak, EmrahMembers of the genus Centaurea (Asteraceae) have been used in traditional plant-based medicine. The methanol extracts of twelve Centaurea species, of which five are endemic to Turkey flora, were screened for antibacterial activity against four bacteria (Escherichia coli, Bacillus cereus, Salmonella enteritidis, Staphylococcus aureus). The antibacterial activity was evaluated by the microdilution method and the minimum inhibition concentrations (MIC) of the extracts were determined. C. cariensis subsp. microlepis exhibited an antimicrobial effect on all tested microorganisms. The extracts from eight Centaurea species (C. balsamita, C. calolepis, C. cariensis subsp. maculiceps, C. cariensis subsp. microlepis, C. kotschyi var. kotschyi, C. solstitialis subsp. solstitialis, C. urvillei subsp. urvillei and C. virgata) possessed antibacterial activity against several of the tested microorganisms.Öğe Antimicrobial activities, toxicity and phenolic composition of Asphodeline anatolica E. Tuzlaci leaf extracts from Turkey(TAYLOR & FRANCIS LTD, 2016) Marino, Andreana; Zengin, Gökhan; Nostro, Antonia; Ginestra, Giovanna; Dugo, Paola; Cacciola, Francesco; Miceli, NataliziaThe antimicrobial activity of acetone, methanol and aqueous extracts of Asphodeline anatolica E. Tuzlaci leaves was evaluated against American type culture collection, food and clinical isolates (Listeria monocytogenes and Staphylococcus aureus including methicillin-resistant strains-MRSA). Biofilm formation, toxicity and characterisation of the polyphenolic content were analysed. The acetone extract demonstrated a higher antibacterial activity against S. aureus including MRSA strains, L. monocytogenes and Pseudomonas aeruginosa than against other extracts. No effect was observed in biofilm formation. The extracts resulted non-toxic against Artemia salina Leach. The phytochemical screening of extracts indicated that they mainly contained six polyphenols identified as catechin 3-O-gallate, protocatechuic acid, diosmin, rutin, cirsimaritin and kaempferol glucoside. This study is the first report on antimicrobial activity and phenolic content of A. anatolica and contributes to enrich the literature data on the biological properties of this plant. A. anatolica leaves have a potential as source of natural antimicrobial compounds.Öğe Antioxidant capacity and fatty acid composition of different parts of Adenocarpus complicatus (Fabaceae) from Turkey(REVISTA DE BIOLOGIA TROPICAL, 2014) Berber, Adnan; Zengin, Gökhan; Aktümsek, Abdurrahman; Şanda, Murad Aydın; Uysal, TunaAdenocarpus complicatus is distributed throughout the Anatolian peninsula and is widely used for human and animal nutrition. The purpose of this work was to study the antioxidant properties and fatty acid composition of different parts of this plant (fruits and mixed materials). The species was collected from Golyuzu village of the Seydisehir district near Konya province, Turkey. Fruit and mixed parts obtained from this species were ground and a 15g sample was used to prepare methanolic extracts. Powdered plant samples were extracted with 100mL methanol in a mechanical shaker. The obtained extracts were filtered and concentrated to dryness under reduced pressure and were subsequently stored at -20 degrees C. Antioxidant components, namely total phenolic and flavonoid content, were detected for each extract using spectrophotometric methods. Antioxidant capacity was evaluated by various assays including phosphomolybdenum, DPPH free radical scavenging capacity, metal chelating activity, and ferric and cupric ion reducing power. The fatty acid profiles of plant parts were also determined by using gas chromatography. The total phenolic content of fruit (36.21mgGAE/g) was higher than that of mixed materials (13.79mgGAE/g). The methanolic extract of mixed material had higher amounts of flavonoid than fruit extract. The free radical scavenging activity of extracts was expressed as IC50 value (mu g/mL) (amount required to inhibit DPPH radical formation by 50%). The lower IC50 value reflects better free radical scavenging action. The radical scavenging activity of the samples was compared with BHT, it showed the mixed material to be almost two times more potent than the fruit extract. However, BHT is an excellent free radical scavenger with an IC50 of 34.061 mu g/mL. The ferric and cupric reducing power potentials of the extracts were expressed as EC50 value (the effective concentration at which the absorbance was 0.5). Fruit extract exhibited strong ferric reducing power with an EC50 of 871.25 mu g/mL. The metal chelating activity of the extracts increased with concentration. Chelating effect was 83.60% for fruit extract at 1mg/mL concentration. Oil content of fruit and mixed parts were detected as 6.71 and 6.14%, respectively. A total of 32 fatty acids were found in the oil. Essential fatty acids (linoleic and alpha-linolenic acid) were identified as the most abundant fatty acids in the oil. These results demonstrated that this plant species can be considered as an alternative to synthetic antioxidants. Likewise, the oil obtained from the plant can be used as a source of essential fatty acids for food and pharmacological applications.Öğe Antioxidant capacity and fatty acid profile of Centaurea kotschyi (Boiss. & Heldr.) Hayek var. persica (Boiss.) Wagenitz from Turkey(INST GRASA SUS DERIVADOS, 2011) Zengin, Gökhan; Güler, Gökalp O.; Çakmak, Yavuz Selim; Aktümsek, AbdurrahmanThe antioxidant capacity of the methanolic extract and the fatty acid composition of C. kotschyi var. persica were investigated. Six different chemical methods were used to determine the antioxidant capacity. The fatty acid composition was analyzed using gas chromatography. The IC50 value of the extract was determined as 37.09 mu g/ml (in the DPPH assay). In the beta-carotene/linoleic acid system, the extract exhibited 65.22% inhibition against linoleic acid oxidation. The amount of total phenolic content and total antioxidant capacity were detected as 36.52 mg gallic acid equivalent (GAE)/g and 74.93 mg ascorbic acid equivalent (AE)/g, respectively. The major fatty acid in the composition of C. kotschyi var. persica was found to be C 18:3 omega 3 (alpha-linolenic acid) by GC analysis. The results presented here indicate that C. kotschyi var. persica possess strong antioxidant properties. Therefore, the species can be used as a natural additive in food, cosmetic and pharmaceutical industries.Öğe Antioxidant Potential and Inhibition of Key Enzymes Linked to Alzheimer's Diseases and Diabetes Mellitus by Monoterpene-Rich Essential Oil from Sideritis galatica Bornm. Endemic to Turkey(ACG PUBLICATIONS, 2016) Zengin, Gökhan; Sarıkürkcü, Cengiz; Aktümsek, Abdurrahman; Ceylan, RamazanThe present study was designated to (1) characterize the essential oil from S. galatica (SGEOs) and (2) evaluate its antioxidant and enzyme inhibitory activities. Antioxidant capacity was tested different methods including free radical scavenging (DPPH, ABTS and NO), reducing power (FRAP and CUPRAC), metal chelating and phosphomolybdenum. Inhibitory activities were analyzed on acetylcholiesterase, butrylcholinesterase, alpha-amylase and alpha-glucosidase. SGEOs were chemically analyzed and identified by gas chromatography and gas chromatography/mass spectrophotometry. 23 components, representing 98.1% of SGEOs were identified. Monoterpene hydrocarbons (74.1%), especially alpha-(23.0%) and beta-pinene (32.2%), were the main constituents in SGEOs. The main sesquiterpene hydrocarbons were beta-caryophyllene (16.9%), germacrene-D (1.2%) and caryophyllene oxide (1.2%), respectively. Generally, SGEOs has shown moderate free radical, reducing power, metal chelating and enzyme inhibitory activities. These activities related to chemical profile in SGEOs. Our findings supported that the possible utility of SGEOs is a source of natural agents for food or pharmaceutical industries.Öğe Antioxidant potentials and anticholinesterase activities of methanolic and aqueous extracts of three endemic Centaurea L. species(PERGAMON-ELSEVIER SCIENCE LTD, 2013) Aktümsek, Abdurrahman; Zengin, Gökhan; Güler, Gökalp Özmen; Çakmak, Yavuz Selim; Duran, AhmetThe methanol and aqueous extracts of three endemic Centaurea species (C. polypodiifolia var. pseudobehen, C pyrrhoblephara and C antalyense) were investigated for their antioxidant and cholinesterase inhibitory activities. The antioxidant activities of these extracts were evaluated by in vitro models including, phosphomolybdenum assay, free radical scavenging assays (DPPH and ABTS), beta-carotene/linoleic acid test system, metal chelating assay, FRAP assay, ferric and cupric reducing power. Cholinesterase inhibitory activities were examined using Ellman's calorimetric method. Total phenol, flavonoid, and saponin contents were also measured. Among the six Centaurea extracts evaluated, the highest antioxidant abilities were obtained from C polypodiifolia var. pseudobehen. Methanolic extracts from C polypodiifolia var. pseudobehen and C antalyense had a noticeable inhibition towards AChE and BChE. These findings suggest that Centaurea species could be an anticholinesterase agent and antioxidant resource in some industries, such as food, pharmacology, and cosmetics. (C) 2013 Elsevier Ltd. All rights reserved.Öğe Antioxidant properties and enzyme inhibitory effects of extracts from Mandragora autumnalis and its fatty acid composition(MARMARA UNIV, FAC PHARMACY, 2016) Uysal, Şengül; Zengin, Gökhan; Aktümsek, AbdurrahmanThe present research was undertaken to evaluate antioxidant activities and enzyme inhibitory potentials of two extracts from two parts of Mandragora autumnalis. The antioxidant properties were evaluated by using different methods [ABTS (2,2-azino-bis (3-ethylbenzothiazloine-6-sulphonic acid)), DPPH (1,1 diphenyl-2-picrylhydrazyl radical), CUPRAC (cupric ion reducing antioxidant capacity), and FRAP (ferric reducing antioxidant power assays)]. Enzyme inhibitory potentials were tested against cholinesterase (AChE and BChE), tyrosinase, a-amylase and a-glucosidase. For phytochemical composition, fatty acids, total phenolics and flavonoid content were investigated. Generally F-Met exhibited the strongest antioxidant effect with the highest level of phenolics. Total phenolic and flavonoid content were determined as 26.10-46.92 mgGAE/g abd 3.60-26.11 mgRE/g, respectively. a- linolenic acid was found to be major fatty acids in the studied oils (33.81 % for flowers and 39.15 % for leaves). The study suggested that M. autumnalis could be valuable as a source of natural agents in food and pharmaceutical applications.Öğe Antioxidant properties of methanolic extract and fatty acid composition of centaurea urvillei DC. subsp hayekiana Wagenitz(ACG PUBLICATIONS, 2011) Zengin, Gökhan; Aktümsek, Abdurrahman; Güler, Gökalp Özmen; Çakmak, Yavuz Selim; Yıldıztugay, EvrenCentaurea is one of most important genera of Turkey flora. Some members of the genus have been used in Anatolian folk medicine. This study was undertaken in order to examine the in vitro antioxidant activities and fatty acid composition of Centaurea urvillei subsp. hayekiana. Antioxidative properties of the methanolic extract was assessed by different in vitro experiments including total phenolic and flavonoid content, phosphomolybdenum assay (total antioxidant capacity), free radical scavenging assay, beta-caroten/linoleic acid bleaching test system, ferric and cupric ion reducing power. According to the results of antioxidant capacity assays, C. urvillei subsp. hayekiana showed moderately antioxidant activity in test methods. Fatty acid analysis was performed by GC and thirty-two fatty acids were identified. The oil of C. urvillei subsp. hayekiana was characterized by higher amounts of C 18:2 omega 6 (linoleic acid) and C 18:1 omega 9 (oleic acid). The results suggested that C. urvillei subsp. hayekiana may be utilized as a source of both natural antioxidant and linoleic acid in healthy medicine and food industry.Öğe Antioxidant properties of methanolic extract and fatty acid composition of Centaurea urvillei DC. subsp. hayekiana Wagenitz(2011) Zengin, Gökhan; Aktümsek, Abdurrahman; Güler, Gökalp Özmen; Çakmak, Yavuz Selim; Yıldıztugay, EvrenCentaurea is one of most important genera of Turkey flora. Some members of the genus have been used in Anatolian folk medicine. This study was undertaken in order to examine the in vitro antioxidant activities and fatty acid composition of Centaurea urvillei subsp. hayekiana. Antioxidative properties of the methanolic extract was assessed by different in vitro experiments including total phenolic and flavonoid content, phosphomolybdenum assay (total antioxidant capacity), free radical scavenging assay, ?-caroten/linoleic acid bleaching test system, ferric and cupric ion reducing power. According to the results of antioxidant capacity assays, C. urvillei subsp. hayekiana showed moderately antioxidant activity in test methods. Fatty acid analysis was performed by GC and thirty-two fatty acids were identified. The oil of C. urvillei subsp. hayekiana was characterized by higher amounts of C 18:2 ?6 (linoleic acid) and C 18:1 ?9 (oleic acid). The results suggested that C. urvillei subsp. hayekiana may be utilized as a source of both natural antioxidant and linoleic acid in healthy medicine and food industry. © 2011 Reproduction is free for scientific studies. © 2011 Reproduction is free for scientific studies.Öğe Antioxidant, Antimicrobial Activity And Dna Protective Effect Of Mespilus Germanica (L)(Selçuk Üniversitesi, 2023 Eylül) Taner Saraçoğlu, Hatice; Arslan, Nursena; Arslan, Emine; Zengin, Gökhan; Gülbahçe Mutlu, ElifAim: Medlar (M. germanica) is a durable plant which have hard fruits. In this study, it was aimed to determine the antioxidant, antimicrobial activity and DNA protective effects of both fruit and seed extracts of medlar. Method: Antioxidant capacities of extracts of medlar was determined by using the DPPH method, Folin-Ciocaltaeu method was used for total phenolic content and the antimicrobial effect of the extract against 16 bacteria was investigated. Findings: As a result of the study, the possible protective effect of medlar fruit extracts obtained at different concentrations against DNA damage was determined. In addition, it was revealed that the total phenolic contents and radical scavenging activities of the seed extracts were higher than the fruits extracts. While the medlar seed extract used in the study did not show any effect against bacteria, the fruit extract of this plant had various effects on the bacteria used. In addition, it was determined that the medlar fruit extract had a protective effect in DNA+UV, DNA+H2O2 and DNA+UV+H2O2 applications. Results: According to the results obtained, it was observed that M. germanica could provide protection against oxidative stress.Öğe Asphodeline Cilicica Tuzlaci: From the Plant to Its Most Active Part Extract and Its Broad Bioactive Properties(ELSEVIER, 2019) Zengin, Gökhan; Aktümsek, Abdurrahman; Mocan, Andrei; Rengasamy, Kannan R. R.; Picot, Carene M. N.; Mahomoodally, Mohamad FawziThis study investigated into the polyphenolic content, antioxidant and enzyme (a-amylase, a-glucosidase, tyrosinase, acetylcholinesterase [AChE], and butyrylcholinesterase [BChE]) inhibitory activities of 12 extracts of the endemic Asphodeline cilicica (AC) Tuzlaci, from Turkey. The total phenolic content for the methanol and acetone extracts of AC roots were 56.52 and 52.96 mg GAEs/g extract, respectively. Both the acetone and methanol extracts of AC roots exhibited an important antioxidant capacity. Likewise, the acetone and methanol extracts of AC roots revealed to be the most potent scavengers of DPPH radical (58.25 and 58.78 mg TEs/g extract). Acetone extract of AC roots inhibited a-amylase showing an acarbose equivalent value (mmol ACAEs/g extract) of 0.27, while against a-glucosidase the value recorded was 2.30. The acetone and methanol extracts of the different plant parts of AC inhibited AChE and BChE, while no/poor activity was noted for the water extracts. In the present study, extracts of AC showed inhibitory activity against key enzymes involved in diabetes and neurodegenerative complications, thereby advocating for the need for in-depth studies geared towards the discovery of pharmacophores from this endemic plant. (c) 2018 SAAB. Published by Elsevier B.V. All rights reserved.Öğe An assessment of phenolic profiles, fatty acid compositions, and biological activities of two Helichrysum species: H. plicatum and H. chionophilum(WILEY, 2020) Acet, Tuba; Özcan, Kadriye; Zengin, GökhanIn the present study, we aimed to search and compare the biological activities of the ethanol (EtOH), methanol (MeOH), and ethylacetate (EtOAc) solvent extracts of the flower, stem, and root parts of two Helichrysum plants (H. chionophilum (Hc) and H. plicatum subsp. plicatum (Hp)). The antioxidant properties were determined by using (2,2-diphenyl-1-picrylhydrazyl) (DPPH) and ABTS (2,2 '-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. The enzyme inhibitory effects of the extracts were investigated on butyrylcholinesterase (BChE), acetylcholinesterase (AChE), alpha-glucosidase, and alpha-amylase. Palmitic acid (C 16:0) was also determined as major fatty acids in the tested oils (31.21%-67.68%). In both plants, it was found that the EtOAc extracts of the flowers had a strong antioxidant and enzyme inhibitory effect. In conclusion, the results obtained in the present study showed that H. chionophilum and H. plicatum can be seen as a promising source for the natural bioactive compounds that can be used in therapeutic applications. Practical applications The members of the genus Helichrysum have been widely taken for therapeutic purposes in traditional medicine as well as food. In this context, we investigated the chemical characterization and biological activities of two Helichrysum species extracts (H. chionophilum and H. plicatum subsp. plicatum). Antioxidant capacity, enzyme inhibition and anti-microbial effects were tested for biological activities. Chemical characterization was identified by high performance liquid chromatography (HPLC) (for phenolic) and gas chromatography-flame ioanization detector (GC-FID) (for fatty acids). Based on our findings, the species may be valuable for designing novel food products.Öğe Assessment of the antioxidant potential and fatty acid composition of four Centaurea L. taxa from Turkey(ELSEVIER SCI LTD, 2013) Aktümsek, Abdurrahman; Zengin, Gökhan; Güler, Gökalp Özmen; Çakmak, Yavuz Selim; Duran, AhmetThis paper focused on the assessment of antioxidant property and fatty acid composition of four Centaurea species. The antioxidant activity of its methanol extract was evaluated by several in vitro experiments including phosphomolybedum assay, DPPH assay, beta-carotene/linoleic acid, ferric and cupric reducing power. Total phenolic and flavonoid contents were also evaluated. The methanol extract of Centaurea pulcherrima var. pulcherrima showed the superior free radical scavenging activity, linoleic acid inhibition capacity, reducing power and also had the highest total phenolic content. A significant relationship between antioxidant capacity and total phenolic components was found. The oils of Centaurea taxa were also analysed for fatty acid concentration by gas chromatography. The principal fatty acids in the species were palmitic acid (23.38-30.49%) and linoleic acid (20.19-29.93%). These findings suggest that the Centaurea species could be used as a potential source of new natural antioxidants and unsaturated fatty acids in food industry, cosmetics and pharmaceutical preparations. (c) 2013 Elsevier Ltd. All rights reserved.Öğe Bazı Centaurea türlerinin bazı biyokimyasal özelliklerinin belirlenmesi(Selçuk Üniversitesi Fen Bilimleri Enstitüsü, 2010-06-04) Zengin, Gökhan; Aktümsek, AbdurrahmanBu çalışmada, üçü Türkiye florası için endemik olan altı Centaurea (Asteraceae) türünün antioksidan kapasiteleri ve yağ asidi komposizyonları araştırılmıştır. Türlerin metanol ekstraklarının antioksidan kapasiteleri total fenolik içerik, total antioksidan kapasite, serbest radikal yakalama testi, ß-karoten/linoleik asit sistemi, indirgeme gücü ve CUPRAC (bakır indirgeme gücü) testini içeren altı farklı kimyasal metotla değerlendirilmiştir. BHA (bütillenmiş hidroksianisol), BHT (bütillenmiş hidroksitoluen) ve askorbik asit standart antioksidan bileşikler olarak kullanılmıştır. Centaurea türlerinin metanol ekstrakları önemli bir antioksidan etkinlik göstermiştir. C. drabifolia subsp. detonsa, C. kotschyi var. persica ve C. pulchella tüm test sistemlerinde diğer türlerden daha güçlü antioksidan özelliklere sahiptir. Türlerin yağ asidi komposizyonları gaz kromatografik sistem (GC) kullanılarak tanımlanmış ve otuz yağ asidi belirlenmiştir. Genel olarak C 18:2 ?6 (linoleik asit) ve C 18:3 ?3 (?-linolenik asit) major yağ asitleri olarak tespit edilmiştir. Bu sonuçlar Centaurea türlerinin doğal antioksidanların ve esansiyel yağ asitlerinin bir kaynağı olarak gıda ve farmakolojik uygulamalarda kullanılabileceğini göstermektedir.