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Öğe Antioxidant potentials and anticholinesterase activities of methanolic and aqueous extracts of three endemic Centaurea L. species(Pergamon-Elsevier Science Ltd, 2013) Aktumsek, Abdurrahman; Zengin, Gokhan; Guler, Gokalp Ozmen; Cakmak, 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 Assessment of the antioxidant potential and fatty acid composition of four Centaurea L. taxa from Turkey(Elsevier Sci Ltd, 2013) Aktumsek, Abdurrahman; Zengin, Gokhan; Guler, Gokalp Ozmen; Cakmak, 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 Comparison of Fatty Acid Compositions and ?3/?6 Ratios of Wild Brown Trout and Cultured Rainbow Trout(Central Fisheries Research Inst, 2017) Guler, Gokalp Ozmen; Zengin, Gokhan; Cakmak, Yavuz Selim; Aktumsek, AbdurrahmanFish are a unique dietary source beneficial to human health. These valuable effects originate from omega 3 polyunsaturated fatty acids, particularly the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the fish oil. In this study, fatty acid composition of the muscle lipids of Salmo trutta macrostigma (wild brown trout) and Oncorhynchus mykiss (cultured rainbow trout) in Gezende Dam Lake were determined by gas chromatographic technique. In both species, palmitic acid (16.26-18.94%), oleic acid (17.88-20.49%) and DHA (14.08-18.49%) were identified as major saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA), respectively. Wild fish contained significantly more linolenic acid, arachidonic acid, eicosapentaenoic acid, docosapentaenoic acid, total omega 3 fatty acids and has higher omega 3/omega 6 ratio than cultured fish. In conclusion, wild brown trout may have a higher nutritional value considering total omega 3 fatty acids (35.52-27.43%) and omega 3/omega 6 ratio (3.84-1.56) compared to cultured rainbow trout.Öğe Evaluation of Fatty Acid Compositions of Yogurts in Turkey(Asian Journal Of Chemistry, 2014) Caglayan, Okan; Cakmak, Yavuz Selim; Guler, Gokalp Ozmen; Zengin, Gokhan; Aktumsek, AbdurrahmanIn this study, fatty acid composition and conjugated linoleic acid content of some yogurts in Turkey were determined. Total 50 yogurt samples belonging to 16 different national yogurt brands were analyzed by using GC. These samples categorized as whole yogurts, light yogurts, probiotic yogurts and fruity yogurts. Generally, palmitic acid (28.840-30.160 %), oleic acid (26.003-27.533 %) and stearic acid (11.413-12.077 %) were major fatty acids. Total conjugated linoleic acid percentages varied between 0.790 and 0.862 %. The results have shown that fatty acids compositions of yogurts have a desirable characteristic for healthy diet when their levels of conjugated linoleic acid contents are considered.Öğe Evaluation of Fatty Acid Compositions of Yogurts in Turkey(Asian Journal Of Chemistry, 2014) Caglayan, Okan; Cakmak, Yavuz Selim; Guler, Gokalp Ozmen; Zengin, Gokhan; Aktumsek, AbdurrahmanIn this study, fatty acid composition and conjugated linoleic acid content of some yogurts in Turkey were determined. Total 50 yogurt samples belonging to 16 different national yogurt brands were analyzed by using GC. These samples categorized as whole yogurts, light yogurts, probiotic yogurts and fruity yogurts. Generally, palmitic acid (28.840-30.160 %), oleic acid (26.003-27.533 %) and stearic acid (11.413-12.077 %) were major fatty acids. Total conjugated linoleic acid percentages varied between 0.790 and 0.862 %. The results have shown that fatty acids compositions of yogurts have a desirable characteristic for healthy diet when their levels of conjugated linoleic acid contents are considered.Öğe A STUDY ON ANTIOXIDANT CAPACITIES AND FATTY ACID COMPOSITIONS OF TWO DAPHNE SPECIES FROM TURKEY: NEW SOURCES OF ANTIOXIDANTS AND ESSENTIAL FATTY ACIDS(Wiley, 2013) Zengin, Gokhan; Arkan, Tuba; Aktumsek, Abdurrahman; Guler, Gokalp Ozmen; Cakmak, Yavuz SelimDaphne (Thymealaceae) species have been widely used in traditional Anatolian medicine. The antioxidant capacity and fatty acid composition of two Daphne taxa (D.oleoides subsp. oleoides and D.serica) were studied. The antioxidant properties of four solvent extracts of Daphne species were assessed using different chemical assays including phosphomolybdate assay, free radical-scavenging assay, -carotene/linoleic acid test system, ferric and cupric reducing power. The total phenolic and flavonoid content of the extracts also were determined. Ethyl acetate, methanol and ethanol extracts obtained from the Daphne species possess strong antioxidant potential. Polyunsaturated fatty acids in the studied oils were the highest level in the fatty acid components. Essential fatty acids accounted for 27.46-45.31% of total fatty acids. These results indicated that the extracts of studied Daphne taxa can be exploited as a source of natural antioxidants and essential fatty acids in pharmacological and food industry.