Σύνθεση λιπαρών οξέων του βασιλικού πολτού και δευτεριωμένων αναλόγων

Ο βασιλικός πολτός είναι μια έκκριση από τους υποφαρυγγικούς αδένες και την κάτω γνάθο των εργατριών μελλισών (Apis mellifera L.). Είναι ένα λευκό-κιτρινωπό, ζελατινώδες, όξινο κολλοειδές, που περιέχει περίπου 5% λίπος. Σε αντίθεση με τα λιπαρά οξέα των περισσότερων ζωϊκών και φυτικών υλών, τα οποία αποτελούνται κυρίως από εστεροποιημένα λιπαρά οξέα, υπό τη μορφή τριγλυκεριδίων, καθένα από τα οποία έχει 14-20 άτομα άνθρακα, τα λιπαρά οξέα του βασιλικού πολτού είναι ελεύθερα, μεσαίας αλυσίδας (8-10 άτομα άνθρακα), ακραία ή/και εσωτερικά υδροξυλιωμένα, με ακραίες μονο- ή δι-καρβοξυλικές ομάδες, κορεσμένα ή μονοακόρεστα στη 2-θέση. Το κυρίαρχο λιπαρό οξύ στον βασιλικό πολτό είναι το trans-10-υδροξυ-2-δεκενοϊκό οξύ (10-HDA) και η ποσότητά του ποικίλλει ανάλογα με την προέλευση και τα χαρακτηριστικά της μέλισσας. Εκτός από αυτό, τα πλέον άφθονα λιπαρά οξέα είναι: το σεβακικό οξύ (δεκανοδιοϊκό οξύ), το 2-δωδεκενοδιοϊκό οξύ, το 10-υδροξυδεκανοϊκό οξύ και το 3-υδροξυδεκανοϊκό οξύ (3-HDA). Στην παρούσα διατριβή, παρουσιάζονται καινοτόμες και εύχρηστες πορείες για τη σύνθεση του trans-10-υδροξυ-2-δεκενοϊκού οξέος και του 2-δωδεκενοδιοϊκού οξέος. Αυτές οι συνθέσεις στηρίζονται σε εκλεκτική διασταυρούμενη μετάθεση, με τη χρήση καταλύτη Hoveyda-Grubbs 2ης γενιάς. Επίσης, μελετήθηκε μέθοδος για τη σύνθεση του trans-10-υδροξυ-2-δεκενοϊκού οξέος, που στηρίζεται σε αντίδραση Wittig. Tέλος, κρίθηκε σημαντική η σύνθεση δευτεριωμένων λιπαρών οξέων, που φέρουν δύο άτομα δευτερίου, καθώς τέτοια προϊόντα έχουν ποικίλες εφαρμογές, τόσο σε μελέτες των πορειών βιοσύνθεσης και αποικοδόμησης, όσο και σε μελέτες με φασματομετρία μάζας υψηλής διακριτικής ικανότητας (HRMS), ως πρότυπες ενώσεις.Royal jelly is a secretion from the hypopharyngeal and mandibular glands of worker bees (Apis mellifera L.). It is a white-yellowish, gelatinous, acidic colloid, containing about 5% fat. Unlike fatty acids of most animal and plant materials, which consist mainly of triglyceride fatty acids each one having 14–20 carbon atoms, royal jelly fatty acids are medium-chained (8–10 carbon atoms) free fatty acids, terminally and/or internally hydroxylated, with terminal mono- or dicarboxylic acid functions, either saturated or monounsaturated at the 2-position. The predominant fatty acid in royal jelly is trans-10-hydroxy-2-decenoic acid (10-HDA). Apart from thisacid, the most abundant fatty acids in royal jelly are: sebacic acid (decanedioic acid), 2-dodecenedioic acid,10-hydroxydecanoic acid and 3-hydroxy-decanoic acid (3-HDA). In this thesis, convenient and useful synthetic routes to trans-10-hydroxy-2-decenoic acid and 2-dodecenedioic acid are presented. These routes are based on selective cross-metathesis, using the second generation Hoveyda-Grubbs catalyst. Also, a method for the synthesis of trans-10-hydroxy-2-decenoic acid, based on a Wittig reaction was studied. Finally, it was important to synthesize deuterated fatty acids containing two deuterium atoms, as such those products may have a variety of applications, both in biosynthesis and degradation studies, and in high resolution mass spectrometry (HRMS) studies as reference compounds

Synthesis and structural properties of ZnO and diatomite-supported ZnO nanostructures

Zinc oxide (ZnO) and diatomite-supported ZnO nanostructures were prepared using a direct precipitation and co-precipitation method, respectively. The morphologies of the prepared nanostructures were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The surface charge of the samples was assessed by zeta potential measurements. The XRD results showed that the size of the prepared nanoparticles were 18 nm, which was consistent with TEM consequences. The FT-IR spectrum clearly indicated the formation of an interfacial chemical bond between Zn and O of prepared samples but ZnO characteristic peaks shifted to lower wave numbers at about 467 cm-1 for diatomite-supported ZnO. Characterization exhibited that the ZnO particles were successfully distributed in the diatomite support. Prepared nanoparticles have potential for different applications owing to processing facility and more economical reagents. © 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.Firat University Scientific Research Projects Management Unit: 2012 NBE 015This project was supported by Ege University Scientific Research Project Unit Project No. 2012 NBE 015 . -

Sorption of Th(IV) onto ZnO nanoparticles and diatomite-supported ZnO nanocomposite: kinetics, mechanism and activation parameters

WOS: 000384108400003In this study, for the first time ZnO nanoparticles and diatomite-supported ZnO nanocomposite have been utilized as adsorbent for the removal of Th(IV) ions from aqueous solutions under different experimental conditions. The Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R) isotherms were used to analyze the equilibrium data. The sorption equilibrium data were fitted well to the Langmuir isotherm with maximum sorption capacities values was found to be 1.105 mmol/g and 0.320mmol/gfor ZnO nanoparticles and diatomite-supported ZnO nanocomposite, respectively. Pseudo-first and pseudo-second order equations, Intraparticle diffusion and Bangham's models were considered to evaluate the rate parameters and sorption mechanism. Sorption kinetics were better reproduced by the pseudo-second order model (R-2 > 0.999), with an activation energy (E-a) of +99.74kJ/mol and +62.95kJ/mol for ZnO nanoparticles and diatomite-supported ZnOnanocomposite, respectively. In order to specify the type of sorption reaction, thermodynamic parameters were also determined. The evaluated Delta G* and Delta H* indicate the non-spontaneous and endothermic nature of the reactions. The results of this work suggest that both of the used materials are fast and effective adsorbents for removing Th(IV) from aqueous solutions and chemical sorption plays a role in controlling the sorption rate.Ege UniversityEge University [2012 NBE 015]This project was supported by Ege University Scientific Research Project Unit Project No. 2012 NBE 015. The research for this paper was carried out at the Institute of Nuclear Sciences, Ege University, Bornova-Izmir, within the frame of ERASMUS Program