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41.
The essential oils from stems, leaves, inflorescences, and both unripe and ripe infructescences of Smyrnium olusatrum L. (Umbelliferae) collected in Greece were obtained by hydrodistillation and analyzed by GC-FID and GC-MS. Fifty-eight components were identified. Among the samples analyzed, the differences observed were mainly quantitative. All oils were characterized by the abundance of sesquiterpenes. The major components of the stem and leaf oils were furanoeremophil-1-one (54.3% and 28.7%, respectively) and curzerene (18.8%, 29.0%). The main constituents of the inflorescence oil were curzerene (38.1%), germacrone (20.2%) and furanoeremophil-1-one (20.0%), while those of the unripe and ripe infructescence oils were 1beta-acetoxy-furanoeudesm-4(15)-ene (22.1%, 30.8%) and curzerene (29.7%, 17.4%).  相似文献   
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Heparan sulfate (HS) and heparin (HP) are functionally important glycosaminoglycans, which interact with a plethora of proteins and participate in several cellular events. They form specific proteoglycans, which are ubiquitously distributed at both extracellular and cellular levels. HS and HP chains vary in the sulfation pattern and the degree of C-5 epimerization of d-glucuronic acid to l-iduronic acid. These modifications are not uniformly distributed within the chain, providing functional oligomeric domains interacting specifically with various effective proteins. The utilization of specific lyases and chemical depolymerization are the commonest procedures used for structural analysis. Di- and oligosaccharide composition of HS can be accurately and sensitively determined by HPLC, CE and MS. Ultraviolet detection is satisfactory enough for unsaturated saccharides and pre-column derivatization with fluorophores and detection with laser-induced fluorescence results in even higher sensitivity. Solid-phase assays can also be used for monitoring interactions with other molecules. In this article the biological significance of HS and HP in health and disease as well as the portfolio of analytical methods that may help to a deeper understanding of their roles in various pathological processes is presented. Such methodologies are of crucial importance for disease diagnosis and the design of novel synthetic sugar-based drugs.  相似文献   
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The uptake of cesium from aqueous solutions (pH 5) using titanium phosphates was investigated in the absence and presence of background electrolyte (0.1 M NaNO3) using a batch technique. The determination of cesium was performed by gamma spectroscopy using 137Cs as tracer. The obtained sorption isotherms could be satisfactorily reproduced by a Langmuir sorption equation. The maximum uptake capacity values (q max) calculated fitting the experimental data by this equation were 167 and 118 mg/g for solutions of initial pH 5 in the absence and presence of background electrolyte. Kinetics data obtained at 293, 308 and 323 K could satisfactorily reproduced by the pseudo-second order equation. It was demonstrated that the new synthesized materials can remove considerable amounts of cesium from aqueous solutions and ion exchange is considered to be the principal mechanism for cesium removal. Toxicity characteristic leaching procedure and desorption tests provided data about the application of the sorbents in environmental remediation.  相似文献   
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The iodide removal from aqueous solutions (initial I?-concentration: 300–5,000 mg/L) by a low and a high molecular weight polyethylenimine-epichlorohydrin resin was investigated both in absence and presence of background electrolytes (NaCl and Na2SO4, ionic strength due to background electrolyte 0.1 M) using a batch technique, 131I as radioactive tracer and high-resolution γ-ray spectrometry. The experiments in absence of background electrolyte were performed using solutions of initial pH 3 and 7, whereas those in presence using solutions of initial pH 3. The results, which demonstrated the high iodide-removal efficiency of both resins, were modeled using the Langmuir and Freundlich isotherm equations. The experimental data were better reproduced using the Langmuir equation. Using this equation maximum sorption capacity values (Q max) of 638.8 and 603.3 mg/g were obtained for the high molecular weight resin from solutions of initial pH 3 and 7 respectively, whereas the corresponding values for the low molecular weight one were slightly lower (552.4 and 507.5 mg/g respectively). The iodide uptake by the resins strongly depended on the presence of competing anions and especially of sulfates. The examination of sections of the I-loaded resins grains by scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) revealed that iodine was evenly distributed throughout the bulk of the resins and not only bound to their surface.  相似文献   
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The perception of reality by biosystems is based on different, and in certain respects more effective, principles than those utilized by the more formal procedures of science. As a result, what appears as random pattern to the scientific method can be meaningful pattern to a living organism. The existence of this complementary perception of reality makes possible in principle effective use by organisms of the direct interconnections between spatially separated objects shown to exist in the work of J. S. Bell.In memory of J. S. Bell.address for 1990–91 as in footnote 2.  相似文献   
48.
Oleuropein (OE) is the cardinal bioactive compound derived from Olea europaea and possesses numerous beneficial properties for human health. However, despite the plethora of analytical methods that have studied the biological fate of olive oil‐derived bioactive compounds, no validated methodology has been published to date for the simultaneous determination of OE, along with all its major metabolites. In this study, a liquid chromatography‐electrospray ionization‐tandem mass spectrometry (LC‐ESI MS/MS) method has been developed and validated for the quantification of OE, simultaneously with its main metabolites hydroxytyrosol, 2‐(3,4‐dihydroxyphenyl)acetic acid, 4‐(2‐hydroxyethyl)‐2‐methoxy‐phenol or homovanillyl alcohol, 2‐(4‐hydroxy‐3‐methoxyphenyl)acetic acid or homovanillic acid, and elenolic acid in rat plasma matrix. Samples were analyzed by LC‐ESI MS/MS prior to and after enzymatic treatment. A solid‐phase extraction step with high mean recovery for all compounds was performed as sample pretreatment. Calibration curves were linear for all bioactive compounds over the range studied, while the method exhibited good accuracy, intra‐ and inter‐day precision. The limit of detection was in the picogram range (per milliliterof plasma) for HT and OE and in the nanogram range (per milliliter of plasma) for the other analytes, and the method was simple and rapid. The developed methodology was successfully applied for the simultaneous quantification of OE and its aforementioned metabolites in rat plasma samples, thus demonstrating its suitability for pharmacokinetics, as well as bioavailability and metabolism studies. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
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In quest for high sensitivities, we developed an ultrahigh capillary electrophoresis (CE) method for the structural analysis of heparin and heparan sulfate (HS) in biologic samples. Heparin and HS were digested with an equi-unit mixture of heparin lyases I, II and III and the obtained Delta-disaccharides were derivatized with the fluorophore 2-aminoacridone. All known twelve non-, mono-, di- and trisulfated Delta-disaccharides were completely resolved in a single run, using 50 mM phosphate buffer, pH 3.5, and reversed polarity at 30 kV. Relative standard deviation in migration times and peak areas as well as day-to-day variance ranged from 0.9 to 2.4%, suggesting a reproducible and precise method. Detection of 2-aminoacridone (AMAC)-derivatives of Delta-disaccharides by UV at 255 nm showed 2.8 and 10 times higher sensitivity than that of derivatized and non-derivatized ones at 232 nm. Laser-induced fluorescence detection with an Ar-ion laser source showed an approximately 100 times higher sensitivity than that obtained at 232 nm of the non-derivatized species. Application of this method to quantitative analysis of Delta-disaccharides derived from porcine intestinal mucosa heparin and bovine kidney HS showed excellent agreement with previously published methods, suggesting an accurate method. The developed method can be easily applied for the disaccharide analysis of heparin/HS at the attomole level with high accuracy, for distinguishing between heparin and HS and may be of value for studying their interactions with matrix effective molecules.  相似文献   
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