Browsing by Author "Yenil N."
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Item Trace element biomonitoring by leaves of Populus nigra L. from Western Anatolia, Turkey(Triveni Enterprises, 2005) Baslar S.; Dogan Y.; Yenil N.; Karagoz S.; Bag H.The West Anatolian Region is one of the most important areas for industrialization, population density and traffic in Turkey. Therefore, the leaves of Populus nigra L. (Salicaceae), which are used as biomonitor to investigate the levels of the trace elements Cd, Pb, Fe, Zn and Cu, were sampled at 30 locations having different pollution levels in the region. The concentrations of elements were determined by atomic absorption spectrometry. The samples were collected at both reference and contaminated locations where iron was found as the priority element. The strong association between a gradient of contamination and concentration in all samples tested indicates that they are reflecting well the environmental changes, and that they appear as appropriate biological indicators of heavy metal contamination.Item Stable spiro-endoperoxides by sunlight-mediated photooxygenation of 1,2-O-alkylidene-5(E)-eno-5,6,8-trideoxy-α-D-xylo-oct-1,4-furano-7-uloses(2005) Çetin F.; Yenil N.; Yüceer L.Sunlight-mediated photooxygenation of 3-O-acetyl and 3-O-methyl derivatives of 1,2-O-alkylidene-5(E)-eno-5,6,8-trideoxy-α-D-xylo-oct-1,4-furano-7- uloses (1a-e) in carbon tetrachloride solution gave stable 4,7-epidioxy derivatives in 4R (2a-e) and 4S (3a-e) configurations. The presence of an endo alkyl, on the 1,2-O-alkylidene group and its size, resulted in an increase of the yield of the 4S isomers. 3-O-Acetyl derivatives yielded products as a mixture of C-7 anomers, whereas 3-O-methyl derivatives gave pure single stereoisomers. © 2005 Elsevier Ltd. All rights reserved.Item Synthesis and antimicrobial activities of two novel amino sugars derived from chloraloses(2010) Yenil N.; Ay E.; Ay K.; Oskay M.; Maddaluno J.The synthesis of 5-amino-5-deoxy-1,2-O-(S)-trichloroethylidene-β-l-arabinofuranose and 6-amino-6-deoxy-1,2-O-(S)-trichloroethylidene-α-d-glucofuranose is described by a simple three- or four-step route. Antibacterial potency of the new compounds was determined using an inhibition zone diameter test. The results show that these compounds have a broad-spectrum activity against Gram-positive, Gram-negative bacteria and Candida albicans. © 2010 Elsevier Ltd. All rights reserved.Item Properties of uranium(VI) adsorption by methyl 3-O-acetyl-5,6-dideoxy-(S)- 1,2-trichloroethylidene-α-D-xylo-hept-5(E)-eno-1,4-furano-uronate(2011) Yusan S.; Yenil N.; Kuzu S.; Aslani M.A.A.In this study the effect of adsorption parameters such as pH, concentration of uranium(VI), shaking time, and temperature on methyl 3-O-acetyl-5,6-dideoxy- (S)-1,2-trichloroethylidene-α-d-xylo-hept-5(E)-eno-1,4-furano-uronate (MOADDTCEXHEFU) for U(VI) ions have been investigated. The adsorption data for uranium(VI) were well-fitted by the Langmuir isotherm. Thermodynamic analysis showed that the value of Go is negative and Ho and S o are positive. These results and a Fourier transform infrared (FTIR) spectrum analysis show that uranium(VI) ions were successfully bonded to this molecule. The affinity of MOADDTCEXHEFU to Th4+, Ba2+, and also Mg2+ is about 10 times higher than uranium(VI). © 2011 American Chemical Society.Item Sorption profile of uranium (VI) from aqueous medium onto 3-O-acetyl-(S)-1,2-O-trichloroethylidene-5,6,8-trideoxy-α-d-xylo-oct-5(E)-eno-1,4-furano-7-ulose (OASOTCETDOXDXOEEFU)(2012) Aslani M.A.A.; Yusan S.; Yenil N.; Kuzu S.Adsorption of uranyl ions onto 3-O-asetil-(S)-1,2-O-trikloroetiliden-5,6,8-trideoksi-α-d-ksilo-okt-5(E)-eno-1,4-furano-7-uloz (OASOTCETDOXDXOEEFU) from aqueous solutions was investigated in batch adsorption experiments. The study has been conducted to investigate the effects of the pH of solution, contact time, initial concentration and temperature for adsorption process. The maximum removal of U(VI) was found to be about 55% at pH 4.0 and initial U(VI) concentration of 50mgL-1. The organic adsorbent material was characterized by Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The experimental isotherm data of uranium sorption were examined using several adsorption models. Adsorption process fitted to Freundlich and Halsey isotherm models. Thermodynamic results showed that the adsorption process was exothermic and spontaneous. © 2012 Elsevier B.V.Item Nitrite in nature: Determination with polymeric materials(University of Sindh, 2018) Yenil N.; Yemiş F.Nitrogen compounds being important for the vital activities of living things are produced by the nitrification process and occurred spontaneously in the nitrogen cycle. Human vital activities are also responsible for the extra nitrogen released into the atmosphere. So, both human and environmental healths are negatively affected by the increasing nitrate and nitrate amounts in water and soil. For this reason, it is aimed to ensure regular control of nitrates and nitrites at certain levels in order to protect the universe and all living things. Their precise and selective determination by various methods is very important. Their determinations can usually be made by using electrochemical, spectrophotometric, chromatographic and titrimetric methods. Nowadays instead of these techniques, sensors are preferred in determining nitrate and nitrite due to their easy, fast, selective and sensitive application properties. Furthermore, polymeric materials have shown great promise for different sensing applications such as gas, humidity, explosive and water pollutants. Sensors, which are developed by polymerization, have very high quality for the determination of nitrite. The highly sensitive results of optical and electrochemical sensors attract the attention of researchers. In this review, different detection methods for nitrite ions and various studies on the preparation of polymeric sensors that can selectively capture the nitrite ions in complex matrices are examined. © 2018, University of Sindh. All rights reserved.Item Carbon Based Electrode Materials and their Architectures for Capacitive Deionization(University of Sindh, 2021) Samejo B.; Gul S.; Samejo S.; Abro N.Q.; Yenil N.; Memon N.The effective desalination and purification devices for seawater/ brackish water treatment are crucial in sustainable progress. Techniques that render high salt removal efficiency and water purification ability at low applied potentials play a central role in sustainable water supplies. One of themis capacitive deionization (CDI) which has drawn significant consideration as a promising deionization technology since the last decade. Desalination efficiency profoundly depends on the utilized electrode material. The most widely used CDI electrodes are carbons due to their cost effectiveness and good stability. However, to acquire high electrosorption capacity, extensive researches are reported with modified carbon materials. CDI cell architectures are equally important for practical high salt removal performance. This review focuses on carbon materials in CDI along with other emerging trends in diverse carbon types, e.g., carbon nanotubes and their composites. Various architectures reported in the literature to improve desalination efficiency are also included here. © 2021, University of Sindh. All rights reserved.Item Click Reactivity of Azide-Modified Polyvinyl Chloride as an Entry to Glycopolymer Scaffolds(Croatian Chemical Society, 2021) Ay E.; Yenil N.We report the synthesis of new carbohydrate/triazole polymers based on poly(viny chloride) (PVC). Azide incorporation into commercially available PVC was carried out using nucleophilic substitution and Cu-catalyzed reaction of the resulting PVC-N3 using three alkynylcontaining acetonide-protected monosaccharides (based on D-glucose and D-galactose) provided a set of PVC-based polymers incorporating a triazolyl linkage with monosaccharide moieties present on the periphery. Modified polymers were characterized by using Fourier transform infrared (FT-IR), Nuclear Magnetic Resonance (1H-NMR and 13C-NMR) spectroscopy, together with thermogravimetric and surface morphological analysis. © 2021 Croatian Chemical Society. All rights reserved.Item Authenticity and chemometrics of nuts(CRC Press, 2022) Hussain F.S.; Memon N.; Yenil N.; Yemiş F.; Mehmood T.[No abstract available]Item Comparative Analyses of Few West Turkish Varieties of Pomegranate (Punica granatum L.) Peels for Phenolic Content Using Liquid Chromatography(Taylor and Francis Ltd., 2023) Yenil N.; Yemiş F.; Sabikoglu İ.; Memon N.; Güler A.In this work, the amounts of phenolic compounds in the peels of four different pomegranate varieties grown in Özdere-İzmir, Turkey were investigated for the first time. Three different extraction processes namely reflux, ultrasonic bath and mixing, were carried out with dry and fresh pomegranate peels for two different periods of 4 and 12 h. The best results for ellagic acid, hesperidin, and quercetin, except resveratrol, were observed in refluxing extraction in MeOH. It is seen that the amounts of ellagic acid obtained from the dry samples are quite good in shorter extraction time (4-h) as 2778, 3376, 5024 and 3115 µg/g, when compared to fresh samples where reduced amounts were obtained as 973, 2046, 3232 and 1822 µg/g. Similarly, the highest ellagic acid quantities were observed in dry and fresh samples as named of İzmir 8; 2624 µg/g and 8761 µg/g, respectively by using HPLC-DAD for longer extraction time (12-h) which was found to negatively affect the phenolics for fresh samples. In fresh samples, extraction is rapid and long heating causes deterioration. As expected, the amount of ellagic acid was higher in the dry ones. The flavonoids hesperidin and quercetin were detected in quite well amounts for most of the samples, also hesperidin was in high as about 85.5 and 73.3 µg/g in one of the samples. Fifteen different phenolics such as ellagic acid, hesperidin, quercetin, resveratrol, catechin, epicatechin, gallocatechin, epigallocatechin, epicatechin gallate, epigallocatechin gallate, cyanidin, delphinidin, malvidin, myricetin, caffeic acid, caftaric acid, p-coumaric acid, gallic acid and ferulic acid were investigated. The antioxidant activity and total phenolic content analyses were also conducted in the methanolic supernatant extracts. DPPH inhibitions of all extracts varied from 47.22% to 93.83% at 4-h and from 36.88% to 94.96% at 12-hour extractions. Furthermore, ANOVA analyzes for ellagic acid and some catechin derivatives was conducted. © 2022 Taylor & Francis Group, LLC.