Yazar "Gökbulut, Alper" seçeneğine göre listele
Listeleniyor 1 - 5 / 5
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Antioxidant activity and luteolin content of Marchantia polymorpha L.(Turkish Journal of Biology, 2012) Gökbulut, Alper; Satılmış, Basri; Batçıoğlu, Kadir; Çetin, Barbaros; Şarer, EnginAbstract: Antioxidant activity of the methanol and ethyl acetate extracts of Marchantia polymorpha L., which grows naturally in Turkey, was tested by DPPH and ABTS methods. According to the applied methods, both extracts exhibited moderate activity. Some phenolic compounds that could be responsible for the activity were investigated by RP-HPLC, qualitatively and quantitatively, in the methanolic extract of liverwort. While caffeic acid, chlorogenic acid, rutin, myricetin, quercetin, and kaempferol were not found in the extract, luteolin as the liable antioxidant agent was determined as 0.0052 ± 0.0002% among the investigated compounds.Öğe Antioxidant and antimicrobial activities and phenolic compounds of selected Inula species from Turkey(Natural Product Communications, 2013) Gökbulut, Alper; Özhan, Onural; Satılmış, Basri; Batçıoğlu, Kadir; Günal, Selami; Şarer, EnginThree Inula species, I. viscosa, I. helenium ssp. turcoracemosa and I. montbretiana, collected from different locations of Anatolia were investigated for their antioxidant and antimicrobial potential, and their total phenolic content and phenolic composition. Antioxidant activities of various extracts of the plant parts were measured using DPPH radical scavenging and ABTS assays. Antimicrobial potential of methanol extracts of the plant parts was determined by the agar dilution method against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Candida tropicalis. All the extracts were more active against Gram-positive bacteria and yeasts than Gram-negative bacteria. The extracts exhibited antioxidant and antimicrobial activities in different concentrations. Total phenolic concentration of the extracts was estimated with Folin-Ciocalteu reagent using gallic acid as standard. The total phenolic content varied widely in different parts of the three tested Inula species, ranging from 21.1 +/- 0.8 to 190.9 +/- 6.1 mg GAE/g extract. Phenolic components, such as chlorogenic acid, caffeic acid, rutin, myricetin, quercetin, luteolin and kaempferol were quantified by HPLC-DAD in the methanol extracts of the Inula species. It was obvious that the antioxidant and antimicrobial properties of the plants were due to the phenolics.Öğe In vitro antioxidant activity total phenolic content and phenolic composition of Inula heterolepis(Planta Medica, 2013) Karacaoğlu, Melek; Gökbulut, Alper; Özhan, Onural; Şarer, EnginInula heterolepis Boiss., a perennial herbaceous plant (15 – 40 cm) widespread throughout the Eastern Mediterranean region, is used topically in folk medicine against loss of appetite, headaches and hemorrhoids. To the best of our knowledge, a few studies were performed on I. heterolepis and in this study, total phenolic content, antioxidant capacity and phenolic composition of the plant were investigated for the first time (1 – 3). Total phenolic content of methanol extracts of aerial parts and roots of the plant was estimated by Folin Ciocalteu method. The aerial parts of the plant was seemed to contain higher amount of total phenolics compared to roots. Antioxidant activities of methanol extracts of flowers, leaves and roots of the plant were evaluated by DPPH radical scavenging and ABTS assays. All the investigated parts of the plant exhibited antioxidant activity in different concentrations. Flower and leaf extracts expressed higher antioxidant activities compared to root extract with lower IC50 values. With regard to the total phenolic content and antioxidant activity results, phenolic composition of the plant was investigated. Some phenolic compounds such as chlorogenic acid, caffeic acid, rutin, myricetin, quercetin, luteolin and kaempferol were analyzed qualitatively and quantitatively in different parts of the plant by RP-HPLC. Various amounts of phenolics in different parts of the plant could be the main occasion for the determined antioxidant potential.Öğe Phenolic compounds and antimicrobial activity of inula sarana boiss(Planta Medica, 2013) Özhan, Onural; Gökbulut, Alper; Günal, Selami; Şarer, EnginThe genus Inula (Asteraceae) has more than hundred species distributed mainly in Europe, Africa and Asia. Inula species are used as a folk medicine due to their anti-inflammatory, antiseptic, antipyretic, hepatoprotective, antitussive and expectorant effects (1). Inula sarana Boiss. is an endemic herb growing wild in southern Turkey (2). Up to now, only one study on this plant has been conducted in Turkey (3). In the coarse of our continuing search on the Inula species, we investigated the total phenolic content, phenolic compounds and the antimicrobial activity of different parts of Inula sarana. Total phenolic content of the plant was estimated using the Folin-Ciocalteu method. The higher amount of total phenolics was found in the aerial parts of the plant. The qualitative and quantitative analysis of the phenolic compounds were performed by RP-HPLC. Our results revealed that while all the investigated parts of the plant contain chlorogenic and ferulic acids; the flowers and leaves also contain gallic acid and luteolin; apigenin was determined only in the flowers. Antimicrobial activity of the flower, leaf and root extracts of the plant were assayed against S. aureus, E. faecalis, A. baumannii, K. pneumoniae, P. aeruginosa, P. vulgaris, E. aerogenes, E. coli, C. albicans and C. tropicalis by using agar dilution method. The flower and root extracts were found to be more active against yeasts compared to bacteria. The flower extract exhibited the most effective antibacterial activity against S. aureus and K. pneumoniae, while the leaf extract is very potent against S. aureus and E. coli.Öğe Radical scavenging activity and vitexin content of Vitex agnus castus leaves and fruits(FABAD Journal of Pharmaceutical Sciences, 2012) Gökbulut, Alper; Özhan, Onural; Karacaoğlu, Melek; Şarer, EnginThe goal of this study was to determine some of the important phenolic constituents of the methanolic extracts of the leaves and fruits of Vitex agnus-castus by RP-HPLC with regard to the results obtained from radical scavenging activity and total phenolic content assays. 1,1-diphenyl-2-picrylhydrazyl (DPPH) test was used to assess the radical scavenging potential of the extracts. Both leaf and fruit extracts exhibited significant radical scavenging activity with IC50 values of 0.449±0.001 mg/mL and 0.612±0.004 mg/mL, respectively. By using Folin-Ciocalteu’s method, the total phenolic content of leaves and fruits of the plant was determined as 123.9±2.281 mg GAE/g extract and 114.5±2.704 mg GAE/g extract, respectively. In continuation of our ongoing studies on the phenolics of Vitex agnus-castus, a simple and accurate HPLC method was used to determine some phenolic compounds such as vitexin, ferulic acid, rutin, and luteolin qualitatively and quantitatively. Contrary to the previous literature, ferulic acid and rutin were determined neither in leaf nor in fruit extracts, while luteolin was determined in trace amount only in fruit extract. Vitexin, one of the important flavonoid constituents of Vitex agnus-castus, was determined in significant amount as 0.252±0.0089% and 0.342±0.0153% in the leaves and fruits, respectively. The results showed that vitexin is partially responsible for the antioxidant potential of the extracts due to its significant amount and the standardization of the extracts should be performed on vitexin by this suitable RP-HPLC method.
