Synthesis of Ammonium-Based Ionic Liquids for the Extraction Process of a Natural Pigment (Betanin)

The use of new synthesized ammonium-based ionic liquids was explored as an alternative to the current process implemented in the betanin extraction from red beet juice, resulting in high yields: 70% and 82%. Betanin is a vegetal pigment that has been applied to a large variety of products in the food industry, which is important, for it can work as a substitute for the red synthetic dyes used nowadays. Additionally, the use of the kosmotropic salt sodium acetate was explored in order to separate the complex formed by the ionic liquid and pigment of interest in a process that combined two techniques: ATPS (aqueous two-phase system) and SOES (salting-out extraction system). The results reveal that the studied techniques could work as a novel process for the extraction of betanin from red beet juice employing ionic liquids, which have not been tested for this purpose in other research.     

Determination of flomoxef in human plasma by liquid chromatography/electrospray ionization tandem mass spectrometry

A specific, sensitive, rapid and reproducible method for the determination of flomoxef in human plasma using high‐performance liquid chromatography–tandem mass spectrometry was developed and validated. Flomoxef was detected using an electrospay ionization method operated in negative‐ion mode. Chromatographic separation was performed in gradient elution mode on a Luna® C₁₈(2) column (3 μm , 20 × 4.0 mm) at a flow rate of 1 mL/min and runtime 3.5 min. The mobile phase consisted of acetonitrile and water containing 0.1% formic acid as additive. Extraction of flomoxef from plasma and precipitation of plasma proteins was performed with acetonitrile with an absolute recovery of 86.4 ± 1.6%. The calibration curve was linear with a correlation coefficient of 0.999 over the concentration range 10–5000 ng/mL and the lower limit of quantification was 10 ng/mL. The intra‐ and inter‐day precisions were <11.8%, while the accuracy ranged from 99.6 to 109.0%. A stability study of flomoxef revealed that it could be successfully analyzed at 4ºС over 24 h, but it was unstable in solutions at room temperature during short‐term storage (4 h) and several freeze–thaw cycles. Copyright © 2013 John Wiley & Sons, Ltd.     

Morphology and composition of NiMoW/P-Al2O3 systems based on the modified support with varied P2O5 content

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The interaction of cationic and anionic porphyrins with the bovine serum albumin in borate buffer

The interaction of water-soluble porphyrins with the bovine serum albumin in borate buffer at pH 8.6 has been studied. The localization of porphyrins in the protein globule has been determined. It was established that the native conformation of albumin upon binding with the porphyrins is preserved, however, the anionic porphyrins are exhibit wedging effect on the albumin domains. The binding constants were obtained from fluorescence spectroscopy data.     

Determination of absolute stereochemistry of natural alicyclic glycosides by 1H NMR spectroscopy without application of chiral reagents--an indication

A study has been made of the 1H NMR spectra of peracetylated beta-glucopyranosides and alpha-arabinopyranosides obtained by reaction of D- and L-glucoses, and L- and D-arabinoses with either (R)- or (S)-2-octanols. The obtained and literature data show that 1H NMR spectra may be used to determine the absolute configuration of the aglycone moieties of some alicyclic glycosides without the need to synthesize derivatives with chiral reagents, as long as the absolute configuration of their monosaccharide moiety is known or vice versa. Spectra of marine steroid glycosides and their acetates containing glycosylated side chains as alicyclic fragments were also examined. It was shown that analysis of 1H NMR spectra for the determination of the absolute configuration is more applicable in the cases when glycosides have the same substitution in the D-ring of the aglycone moiety.     

The first solid phase synthesis of pincer palladium complexes

Both dimeric μ-chlorine bridged and monomeric bidentate Pd(II) complexes with SCN hybrid pincer-type ligands, bearing thiophosphoryl group and imine moiety of the benzothiazole ring as coordination arms, formed in the reaction with (PhCN)(2)PdCl(2) under kinetic control (20 °C, dichloromethane solution) were readily converted into the corresponding SCN pincer complexes via solid phase synthesis (neat, 200 °C, 15 min). The synthesis of pincer complexes can be performed also by heating (200 °C, 5 min) of a homogeneous mixture of the initial reactants, namely, the ligand and (PhCN)(2)PdCl(2), obtained by manual grinding in a mortar. The efficacy of solid phase approaches is comparable with the analogous synthesis in solutions under severe conditions.     

Noble metals in polyoxometalates

Polyoxometalates containing noble metal ions, such as ruthenium, osmium, rhodium, palladium, platinum, silver and gold, are a structurally diverse class of compounds. They include both classical heteropolyanions (vanadates, molybdates, tungstates) in which noble metals are present as heteroatoms, as well as the recently discovered class of polyoxometalates with noble metal "addenda" atoms. The focus of this Review is on complexes that should, in principle, exist as discrete molecular species in solution, and which are therefore of interest for their reactivity, their future synthetic utility and potential applications, for example, in catalysis or nanoscience.     

Transmission electron microscopy of Ca oxide nano- and microcrystals in α-tricalcium phosphate prepared by sintering of β-tricalcium phosphate

Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to study the porous and non-porous α-tricalcium phosphate (α-Ca₃(PO₄)₂, α-TCP) prepared through a sintering procedure at 1200–1400 °C of β-tricalcium phosphate (β-Ca₃(PO₄)₂, β-TCP). The interpretation of experimental and calculated X-ray and electron diffraction patterns showed that the final product at 1400 °C was primarily α-TCP but roughly 3.0–8.0 wt.% of the starting β-TCP phase and up to 8.0 wt.% of CaO were in the final product. TEM images and electron diffraction patterns showed that the CaO phase – formed by decomposition of TCP – exists as micron-sized areas of various oriented nanocrystals embedded into the bulk α-TCP material and also as self-standing spherulite particles of a few microns in size. Surprisingly, formation of CaO from TCP decomposition occurred at temperatures below those predicted from the phase diagram of the CaO–P₂O₅ system.     

The First Observation of 4f-Luminescence in New Heteronuclear Lanthanide–Germanium Complexes

New lanthanide–germanium complexes with diethylenetriaminepentaacetic acid (DTPA) have been synthesized and were characterized by means of elemental analysis, IR-, UV-absorption and luminescent spectroscopy. The 4f-luminescence of heteronuclear Ln(Ge-DTPA)2 (Ln=Sm, Eu, Tb, Dy) complexes in aqueous solutions was investigated for the first time.