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Öğe Antioxidant and Tyrosinase Inhibitory Activities of Flavonoids from Trifolium nigrescens Subsp petrisavi(Amer Chemical Soc, 2013) Demirkiran, Ozlem; Sabudak, Temine; Ozturk, Mehmet; Topcu, GulactiTrifolium nigrescens was researched for its chemical constituents for the first time. Bioassay-guided isolation of the EtOAc extract from the leaves of T. nigrescens resulted in the purification of a new biflavone, 4',5,5 '',7,7 ''-pentahydroxy-3',3'-dimethoxy-3-O-beta-D-glucosyl-3 '',4'-O-biflavone (1) along with eleven known compounds consisting of three phenolics (2-4), and eight flavonoid glycosides (5-12). Their structures were determined by extensive ID and 2D NMR, and MS data analyses. The isolated compounds were evaluated for their antioxidant activity and inhibitory activity on mushroom tyrosinase. Highly potent inhibitions Were found by compounds 7 (IC50 = 0.38 mM), 8 (IC50 = 0.19 mM), and 12 (IC50 = 0.26 mM) when compared with standard tyrosinase inhibitors kojic acid (IC50 = 0.67 mM) and L-mimosine (IC50 = 0.64 mM). The antioxidative effect of the isolated compounds and the extracts were determined by using, beta-carotene-linoleic acid, DPPH center dot scavenging, ABTS(+center dot) scavenging, superoxide scavenging, and CUPRAC assays. The experimental findings indicated that all the compounds demonstrated activity in all antioxidant activity tests employed except for the compounds 2-6. Compounds 2-6 showed moderate activity only in ABTS(+center dot) scavenging assay. The new compound 1 exhibited better activity than standard alpha-tocopherol in DPPH center dot scavenging, and ABTS(+center dot) scavenging assays. The results show that T. nigrescens can be regarded as a potential source of antioxidant compounds and tyrosinase inhibitors of significance in both the pharmaceutical and food industries.Öğe Determination of trace elements in soil and sunflower (Helianthus annuus L.) plant parts(Parlar Scientific Publications (P S P), 2007) Sabudak, Temine; Seren, Gulay; Kaykioglu, Gul; Dincer, Ali RizaTrace elements are currently of environmental concern. They are harmful to humans, animals and tend to bioaccumulate into the food chain. In this study, the concentrations of trace elements in soil and sunflower plant parts have been investigated. The concentrations of copper, manganese, iron, zinc in soil and sunflower plant samples collected from 5 different locations in Corlu, Turkey were determined by flame atomic absorption spectrometry after wet ashing. The maximum concentrations of trace elements per kg soil were 6.37 mg Cu, 0.53 10(3) mg Mn, 1.05 10(3) Mg Fe, and 36.07 mg Zn. The orders of their concentrations in soils and plant parts were found to be Fe>Mn>Zn>Cu. The maximum metal concentrations, except for Fe concentration, were observed in the leaves and seeds of plant parts. In addition, the sunflower leaves collected at locations 4 and 5 were observed for phytotoxic Mn concentration.Öğe Fatty acid composition of seed and leaf oils of pumpkin, walnut, almond, maize, sunflower and melon(Springer, 2007) Sabudak, Temine[Abstract Not Available]Öğe Flavonoids from Trifolium resupinatum var. microcephalum(Springer, 2007) Isik, Emel; Sabudak, Temine; Oksuz, Sevil[Abstract Not Available]Öğe Lipid constituents of Trifolium resupinatum var. microcephalum(Taylor & Francis Ltd, 2007) Sabudak, Temine; Isik, Emel; Oksuz, SevilThe two new compounds (3-methyl-l-nonene-3-ol and 2',3'-dih,ydroxy propyl pentadecanoate) and four known compounds were isolated from Trifolium resupinatum L. var. microcephalum Zoh. (Leguminosae). All the compounds were reported for the first time from this plant. The stuructures of the isolates were determined by I D, 2D NMR techniques and MS spectroscopy.Öğe A new biflavonoid from Solanum dulcamara L. and investigation of anti-hyperglycaemic activity of its fruit extract(Taylor & Francis Ltd, 2015) Sabudak, Temine; Kaya, Oktay; Cukurova, ElifA new biflavone, 6,2 ',3 '',5 '',4'-pentahydroxy-3,7 ''-biflavone, has been isolated from the fruits of Solanum dulcamara L., in addition to two known compounds, beta-sitosterol and stigmasterol. Their structures were established on the basis of UV, IR, 1D, 2D NMR and HR-ESI-MS spectroscopic methods. The anti-hyperglycaemic effect of S. dulcamara was investigated using diabetic rats. The anti-hyperglycaemic activity of the fruit extract of S. dulcamara was presented for the first time in this study.Öğe Phenolic compounds from Trifolium echinatum Bieb. and investigation of their tyrosinase inhibitory and antioxidant activities(Pergamon-Elsevier Science Ltd, 2013) Sabudak, Temine; Demirkiran, Ozlem; Ozturk, Mehmet; Topcu, GulactiTwo bischromones, 3,3'-dimethoxy-2'-oxychromone (1), 3,3'-dihydroxy-2,2'-oxychromone (2) and a biflavone, 5,7,4',5 '',3''',4''''-hexahydroxy-3 ''-O-beta-glucosyl-3',7 ''-O-biflavone (3) have been isolated from whole plant of Trifolium echinatum Bieb. together with five known fiavonoids. The structures of the compounds were elucidated by 1D and 2D NMR analysis as well as HRESIMS. The isolated compounds were investigated for their antioxidant activity and tyrosinase inhibitory activity. Highly potent inhibition was found for compounds 1 (IC50 = 0.41 mM), 5 (IC50 = 0.47 mM) and 8 (IC50 = 0.45 mM) compared to those of standard tyrosinase inhibitors kojic acid (IC50= 0.67 mM) and L-mimosine (IC50 = 0.64 mM). The antioxidative effect of the extracts was determined by using beta-carotene-linoleic acid, DPPH. scavenging, ABTS(+-) scavenging, and CUPRAC assays. The experimental findings indicated that the compounds 2 and 8 were found to be active in radical scavenging and CUPRAC assays. (C) 2013 Elsevier Ltd. All rights reserved.Öğe Potent tyrosinase inhibitors from Trifolium balansae(Taylor & Francis Ltd, 2006) Sabudak, Temine; Khan, Mahmut Tareq Hassan; Choudhary, M. Iqbal; Oksuz, SevilTrifolium balansae ( Leguminosae) yielded a phytylester, phytyl-1-hexanoate, three steroids, stigmast-5-ene-3 beta,26-diol, stigmast-5-ene-3-ol and campesterol, and an alcohol, pentacosanol which were reported for the first time from T. balansae. The structures of the isolates were determined by 1D and 2DNMR techniques and MS spectroscopy. Compounds 1 - 5 were tested for their enzyme tyrosinase activity. While compounds 1 and 5 did not show any inhibition against the enzyme tyrosinase, compounds 2, 3, and 4 exhibited potent inhibition against tyrosinase. Highly potent ( IC50 = 2.39 mu M) inhibition was found by compound 2, when compared with the standard tyrosinase inhibitors Kojic acid and L-mimosine.Öğe Synthesis and Structural Investigations of Copper Abietat Complexes(Asian Journal Of Chemistry, 2012) Yildiz, Aylin; Sabudak, Temine; Mikailzade, Faik; Kazan, Sinan; Feyizoglu, AdilhanThe purpose of this study is to remove copper from wastewater by preparing copper abietat using abietic acid which exists in sunflower oil. For this, initially the abietic acid present in sunflower oil was obtained. Then copper abietat complex was obtained by extraction of these compounds at different pH values. The structure of copper abietat obtained at the appropriate pH range was studied using infrared spectroscopy, nuclear magnetic resonance and electron paramagnetic resonance techniques.Öğe Trifolium L. - A Review on its Phytochemical and Pharmacological Profile(Wiley, 2009) Sabudak, Temine; Guler, NecmettinPlants from the genus Trifolium have been used in traditional medicine by many cultures. In Turkish folk medicine, for example, some Trifolium species are used for their expectorant, analgesic, antiseptic properties and also to treat rheumatic aches. Some species are also grown as pasture crops for animals in the Mediterranean. The high quercetin concentration and soyasaponin occurrence make the seeds of some Trifolium species a potential source of health beneficial phytochemicals for use in human nutrition. However, Trifolium pratense has also gained popularity due to research into its use for the treatment for menopausal symptoms. This paper provides an overview of the phytochemical and pharmacological profile of Trifolium species. Copyright (C) 2008 John Wiley & Sons, Ltd.Öğe Two new compounds from Trifolium resupinatum var. microcephalum(Taylor & Francis Ltd, 2008) Sabudak, Temine; Isik, Emel; Oksuz, SevilAn investigation of CH2Cl2 and EtOH extracts of Trifolium resupinatum L. var. microcephalum Zoh. has led to the isolation of two new compounds characterized as 4,15-dimethyl-2-(1,2-dihydroxyethyl)-hexadecene (1) and 1-undecene-1-O--2',3',4',6'-tetraacetyl glucopyranoside (2a). Their structures were established by 1D and 2D NMR techniques, and mass spectroscopy.
