Selim Erdogan

Pressurized liquid extraction of phenolic compounds from Anatolia propolis and their radical scavenging capacities.

Propolis samples from important honey producing locations of Anatolia namely; Bingol (BG), Rize (RZ), Tekirdag (TK) and Van (VN), were evaluated for their antiradical capacities, total phenolic contents and individual phenolic compounds which was recovered by means of pressurized liquid extraction (PLE). Several extraction parameters of PLE such as; temperature, pressure, solvent type, extraction time and cell size were investigated for their effects on the extraction performances. The results showed that, 40 °C, 1500 psi, Ethanol:water:HCl; (70:25:5, v/v/v) containing 0.1% tert-butylhydroquinone (tBHQ) as solvent, three extraction cycles within 15 min, and a cell size of 11 mL was the most favorable PLE operating conditions. Results of the tests performed to designate the success of the polyphenol analysis showed that the recovery was in the range of 97.2% and 99.7%. Major phenolic compounds in all samples were found to be gallocatechin (GCT), catechin (CT), epicatechin gallate (ECTG), caffeic acid (CA), chlorogenic acid (ChA), and myricetin (Myr). ChA level of BG propolis was 4.5, 3 and 23 times higher than that of RZ, TK and VN region, respectively. Antiradical tests showed that all propolis samples have superior antiradical capacities up to 500 mg Trolox equivalent activity per gram of extract.

Chemical composition, antimicrobial, insecticidal, phytotoxic and antioxidant activities of Mediterranean Pinus brutia and Pinus pinea resin essential oils.

Essential oils of the resins of Pinus brutia and Pinus pinea were evaluated for their biological potential. Essential oils were characterized using GC-MS and GC/FID. in vitro antimicrobial, phytotoxic, antioxidant, and insecticidal activities were carried out using the direct contact and the fumigant assays, respectively. The chemical profile of the essential oils of the resins of P. pinea and P. brutia included mainly α-pinene (21.39% and 25.40%), β-pinene (9.68% and 9.69%), and caryophyllene (9.12% and 4.81%). The essential oils of P. pinea and P. brutia exerted notable antimicrobial activities on Micrococcus luteus and Bacillus subtilis, insecticidal activities on Ephestia kuehniella eggs, phytotoxic activities on Lactuca sativa, Lepidium sativum, and Portulaca oleracea, as well as antioxidant potential. Indications of the biological activities of the essential oils suggest their use in the formulation of ecofriendly and biocompatible pharmaceuticals.

How safe is the use of herbal weight-loss products sold over the Internet?

Background: In recent years, the use of herbal weight-loss products sold over the Internet has rapidly increased; however, the safety of these products has not been well documented yet. More importantly, the declared ingredients in these products could be different than the marketed contents. Methods: Nine different herbal weight-loss products sold over the Internet were obtained. The ingredients of each product were analyzed in the Laboratory of Forensic Medicine and the Scientific and Technological Research Laboratory of Inonu University. Results: Although all studied weight-loss products were presented as pure herbal, three of them contain sibutramine, three contain caffeine, and three contain caffeine + temazepam. The amount of sibutramine in each capsule was found to be over 10 mg. We analyzed toxic and trace element levels of nine herbal products and found that these herbal products, even in low amounts, contain Pb, Al, Ni, and Ba. Conclusions: Our results indicate that herbal weight-loss products available without prescription and claimed to be purely herbal may contain pharmaceutical substances like sibutramine or temazepam in high doses. Moreover, they also may become contaminated with toxic metals. Since people commonly use these products unaware of its real constituents and without the suggestion or control of a physician, they might cause various health problems some of which might be harmful. Strict legal rules and control mechanisms must be established to minimize their possible harmful effects.

Role of vagal activity on bradicardic and hypotensive effects of caffeic acid phenethyl ester (CAPE)

Caffeic acid phenethyl ester (CAPE) is a phenolic active component of propolis of honeybee hives and reduces heart rate and blood pressure in rats. The objective of this study was to investigate the role of vagal activity and atropine blockage on the bradycardic and hypotensive effects of CAPE in rats. The rats were divided into five groups (n=8). Saline and vehicle (10% ethanol) of CAPE were given to the first and second groups, respectively. Group 3 was treated with 5 mg/kg CAPE. Group 4 bivagotomized and treated with 5 mg/kg CAPE. Group 5 treated with atropine (5 μg/μL/min) continuously and treated with CAPE. The electrophysiological monitoring was done for each experiment under urethane anaesthetize. As a result, CAPE caused intense and transient bradycardia and hypotension. Vagotomy completely abolished bradycardia occurred via CAPE injection; however atropine attenuated bradycardic effects of CAPE. On the other hand, hypotensive effect of CAPE was affected from neither bilateral vagotomy nor atropine treatment. It was thought that CAPE may exert its effects on heart rate via a central parasympathetic control mechanism, but not on central parasympathetic blood pressure control system.

Evaluation of polyphenol contents in differently processed apricots using accelerated solvent extraction followed by high-performance liquid chromatography–diode array detector

Concentrations of 17 polyphenols in ripe-fresh, sun-dried and sulfited-dried apricots either harvested from organic or pesticide-treated trees before harvest were determined using reverse-phase high-performance liquid chromatography with UV–Vis diode array detector, and the change of polyphenol profile with origin of the apricot product was established. Extraction of polyphenols was achieved using the accelerated solvent extraction technique (ASE). A mixture of methanol, water (70:30 v/v) including 0.1 g of tert-butylhydroquinone as solvent, 60 min extraction time, 60°C temperature and 1,500 psi pressure were found the most productive operating conditions for ASE. Concentrations of polyphenols in organic apricots were higher than pesticide-treated samples, and roughly the same in ripe-fresh and sun-dried apricots. Polyphenol concentrations of either organic or pesticide-treated sulfited-dried apricots were lower than the ripe-fresh apricots. Considering the organic ripe-fresh apricots, there was a decrease in some polyphenol concentration in the sulfited-dried apricots compared with the ripe-fresh apricot, and the range of decrease is between 1.4 and 53%.

A new approach to the determination of folic acid at trace levels: using a Fe(III)-folic acid complex to amplify analytical signal

A fast, efficient, cost-effective, and environmental-friendly analytical methodology was developed for preconcentration and determination of trace folic acid in food samples prior to high performance liquid chromatography with diode array detection (HPLC-DAD). The method is based on formation of stable complexes between folic acid and Fe(III) ions at pH 8.0. The formed complexes were extracted to a nonionic surfactant phase containing PONPE 7.5. The surfactant rich phase (SRP) was separated by decantation and diluted with 300 μL of a mixture of 1 M HCl and methanol at a 1 : 1 ratio. The parameters and variables that affected the method were also investigated and optimized in detail. The limit of detection (LOD) of folic acid was 6.06 ng mL−1, the linear range of quantitation for folic acid was 20–1200 ng mL−1 and the correlation coefficients of the calibration curves were 0.9976. The average recoveries and relative standard deviations in the analysis of real samples were in the range of 95.1–105.1% and 1.73–5.25%, respectively. After validation of the method was carried out, the method was applied to the determination of folic acid in real samples, including baby foods, vegetables, cereals, and pharmaceutical samples.

Heavy metal pollution and physiological changes in the leaves of some shrub, palm and tree species in urban areas of Adana, Turkey

Abstract The effects of anthropogenic pollution on metal accumulation and some physiological parameters were investigated in plant leaves in the Adana, located in the Mediterranean region of Turkey. Washingtonia filifera L., Eucalyptus camaldulensis L., Phoenix dactylifera L., Platanus orientalis L., Citrus aurantium L., Nerium oleander L. and Schinus molle L. plants were collected from four different locations having different pollution levels in Adana. Concentrations of metals (Al, B, Ba, Fe, Pb, Sr and Zn), pigment (chloropyhll and carotenoid), lipid peroxidation product (malondialdehyde), and peroxidase (POD) enzyme activity were determined in the leaf tissues of these plants. Nerium oleander was determined to be a suitable biomonitor for heavy metal accumulation from anthropogenic and traffic activities in Adana. It was also determined that S. molle accumulated more Cu, Pb and Zn than all the other plant species and that metal accumulation did not cause a significant increase in pigment content of this plant. Our results indicate that POD enzyme activities in P. orientalis (Sr and Zn), C. aurantium (Ba) and N. oleander (Cu and Pb) can be used as suitable indicators for heavy metal stress. Additionally, we propose that S. molle can be used as a biomonitor for Pb, Cu and Zn, while N.oleander can be used as a biomonitor for Fe, Al, and Ba.

Chemical Composition of the Essential Oil from Cupressus sempervirens L. horizontalis Resin in Conjunction with its Biological Assessment

Abstract Essential oil from the crude oleoresin of C. sempervirens L. was hydro-distillated and analysed by GC and GC-MS. The significant fraction of the essential oil constituted both monoterpene hydrocarbons (46.03 %) and oxygenated monoterpenes (17.27 %). The major components were mainly α-pinene (35.60 %), followed by trans-pinocarveol (5.22 %), α-phellandrene-8-ol (4.56 %), β-pinene (3.06 %), D-limonene (2.83 %), borneol (2.34 %) and camphene (2.15 %). Antibacterial assays indicated the moderate level effectiveness on all tested gram positive and negative bacteria. The most sensitive bacteria were Staphylococcus aureus (ATCC 29213) and Staphylococcus aureus (ATCC 95923) followed by Micrococcus luteus (NRLL B-4375). Insecticidal activity of the essential oil exposure (48 h) on Ephestia kuehniella eggs showed 20.83 % mortality at 100 μL L-1 air concentration. In the antioxidant assays, essential oil revealed a moderate level of the radical scavenging effect against DPPH and total phenolic content. Reducing power of the essential oil appeared to higher when compared to DPPH scavenging activity. Total phenolic content of the essential oil seemed to be well correlated with the assays of the DPPH and reducing power.

Particle size effect of raw material on the pore structure of carbon support and its adsorption capability

ABSTRACT In this study, a series of activated carbons were prepared from Tuncbilek lignite with different particle size by chemical activation. The effect of particle size of lignite on the pore structure of activated carbon and the adsorption kinetics of crystal violet (CV) onto these activated carbons was investigated. BET surface area values of activated carbon samples were determined in the range of 940–1054 m2 g−1. Adsorption capacity of CV onto activated carbons was investigated in a batch system by considering the effects of various parameters such as initial dye concentration, agitation time and adsorption temperature. The Langmuir and Freundlich isotherms were used to describe the adsorption equilibrium studies. The adsorption kinetics of CV has been discussed using the pseudo-first-order, pseudo-second-order and intraparticle diffusion models. Results show that the pseudo-second-order kinetic equation could describe the adsorption kinetics for CV onto activated carbons. Using the thermodynamic equilibrium coefficient obtained at different temperatures and for the initial dye, the thermodynamic constants of adsorption (ΔG°, ΔH° and ΔS°) were also evaluated.

Fractionation and Speciation of Cu in Different Processing Apricots

An analytical procedure was proposed to study the operational fraction of Cu in ripe-fresh, sun-dried and sulphited-dried apricots harvested from either treated Bordeaux mixture or unexposed trees. Based on the methods that consists pressurized liquid extraction procedure and solid phase extraction to separate diverse Cu fractions on different sorbents such as Dowex 50Wx8-40 and Amberlite XAD-7, and then flame atomic absorption spectrometry (FAAS) and ion selective electrode were used for off-line determination of Cu concentrations in the effluents obtained.Total copper concentrations in different processing the apricot samples exposed to Bordeaux mixture were 4.58, 4.48 and 4.25 μg/g in ripe fresh, sun-dried, sulphuring-sun drying, respectively. However, Cu concentrations in the organic apricot samples were determined 2.92; 2.97 and 2.25 μg/g. While circa 40-59% of total copper are extractable with water solvent including about 67-68% cationic copper, 25-33% organically bound copper and 26- 44% labile in Kabaasi apricot samples. Besides, while about 27-48% of total copper are extractable with methanol: water solvents containing about 40-23% cationic copper, 60-78% organically bound copper and 56-71% of copper was absorbed in the stomach.It was applied to analytical procedures for Cu speciation in the apricot samples were verified and validated.