Huseyin Sahin
Giresun University, Espiye M. Y. O, Faculty Member
Research Interests:
Research Interests:
Research Interests:
Comparison of Antioxidant Properties of Wild Blueberries (Vaccinium arctostaphylos L. and Vaccinium myrtillus L.) with Cultivated Blueberry Varieties (Vaccinium corymbosum L.) in Artvin Region of Turkey Artvin Yöresine Ait Doğal Yaban Mersini (Vaccinium arctostaphllos ve Vaccinium myrtillus) ile ...more
Available online, ISSN: 2148-127X Vaccinium arctostaphylos L. and Vaccinium myrtillus L. which are found naturally in most part of Blacksea Region, and Artvin are generally called bear grape, Trabzon tea, and likapa. In addition,... more
Available online, ISSN: 2148-127X Vaccinium arctostaphylos L. and Vaccinium myrtillus L. which are found naturally in most part of Blacksea Region, and Artvin are generally called bear grape, Trabzon tea, and likapa. In addition, different varieties of blueberry (Vaccinium corymbosum L.) have been cultivated in Artvin region for 5 or 6 years. Blueberries contain appreciable levels of phenolic compounds, including anthocyanins and flavonols that have high biological activity. V. arctostaphylos and V. myrtillus show that natural distrubition with received V. corymbosum of different cultured species in Artvin region will be determined antioxidant activity in this study. In this study showed that wild species had a higher antioxidant effect than cultivated species. V. myrtillus had high total polyphenols (11.539-20.742 mg GAE/g dry sample), flavonoids (1.182-2.676 mg QE/g dry sample) and anthocyanins (3.305-11.473 mg Cyn/g dry sample) than V. corymbosum species. In addition, wild specie...
Research Interests:
Research Interests:
Tea with different parts (flower, leaf, seed) of Sideritis condensate infused at different temperatures (60 and 100°C) and times (5, 10 and 30 minutes) were assessed for their phenolic composition and antioxidant activities. Leaf tea had... more
Tea with different parts (flower, leaf, seed) of Sideritis condensate infused at different temperatures (60 and 100°C) and times (5, 10 and 30 minutes) were assessed for their phenolic composition and antioxidant activities. Leaf tea had the highest total phenolic content where as seed tea had the lowest.Leaves soaked at 100°C for 10 minutes had the highest total phenolic content. Total phenolic content of flower tea increased with increase in extraction temperature and time. Radical scavenging activities of leaves infused at 60°C for 5, 10 and 30 minutes were statistically in the same group but lower than those of leaves soaked at 100°C for 5, 10 and 30 min. The major phenolic compound identified from almost all aqueous infusions was the p-coumaric acid. The conditions of tea prepared from leaves of the Sideritis condensata at 100°C for 5, 10 and 30 minutes are the most appropriate conditions in regard to extraction of the highest total phenolics and the strongest antioxidant activ...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
An α-carbonic anhydrase (CA, EC 4.2.1.1) was purified and characterized kinetically from erythrocytes of the sturgeon Acipenser gueldenstaedti, an endangered species. The sturgeon enzyme (AgCA) showed kinetic parameters for the CO(2)... more
An α-carbonic anhydrase (CA, EC 4.2.1.1) was purified and characterized kinetically from erythrocytes of the sturgeon Acipenser gueldenstaedti, an endangered species. The sturgeon enzyme (AgCA) showed kinetic parameters for the CO(2) hydration reaction comparable with those of the human erythrocytes enzyme hCA II, being a highly active enzyme, whereas its esterase activity with 4-nitrophenyl acetate as substrate was lower. Sulphonamide inhibitors (acetazolamide, sulphanilamide) strongly inhibited AgCA, whereas metal ions (Ag(+), Zn(2+), Cu(2+) and Co(2+)) were weak, millimolar inhibitors. Several widely used pesticides (2,4-dichlorophenol, dithiocarbamates, parathion and carbaryl) were also assayed as inhibitors of this enzyme. The dithiocarbamates were low micromolar AgCA inhibitors (IC(50) of 16-18 μM), whereas the other pesticides inhibited the enzyme with IC(50)s in the range of 102-398 μM. The wide use of dithiocarbamate pesticides may be one of the factors enhancing the vulnerability of this sturgeon species to pollutants.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
ABSTRACT Helichrysum species (Asteracea) are widely found in Anatolia. Helichrysum species has used ethnomedicine for centuries. We report here the total phenolic contents and antioxidant activities of the methanolic extracts of... more
ABSTRACT Helichrysum species (Asteracea) are widely found in Anatolia. Helichrysum species has used ethnomedicine for centuries. We report here the total phenolic contents and antioxidant activities of the methanolic extracts of Helichrysum plicatum DC. subsp. plicatum species, together with their HPLC analysis results of individual some phenolic acids and flavonoids. 17 different phenolic constituents were measured by reverse phasehigh performance liquid chromatograpy (RP-HPLC) in the three parts of the plant. Total phenolic compound and ferric reducing antioxidant power (FRAP) were used as antioxidant capacity determinants. All parts of the plants showed high antioxidant activity containing large amounts of antioxidant compounds. Chlorogenic acid, quercetin and rutin found in the three parts of the samples as main phenolic components and absisic, ferulic, epicathecin and cinnamic acids have minor concentration or haven’t been detected at all. The methanolic extracts of the plants proved to be a good source of phenolic compounds and antioxidants agents that might serve to protect health and fight against several diseases.