A Novel qNMR Application for the Quantification of Vegetable Oils Used as Adulterants in Essential Oils

Essential oils (EOs) are more and more frequently adulterated due to their wide usage and large profit, for this reason accurate and precise authentication techniques are essential. This work aims at the application of qNMR as a versatile tool for the quantification of vegetable oils potentially usable as adulterants or diluents in EOs. This approach is based on the quantification of both ¹H and ¹³C glycerol backbone signals, which are actually present in each vegetable oil containing triglycerides. For the validation, binary mixtures of rosemary EO and corn oil (0.8–50%) were prepared. To verify the general feasibility of this technique, other different mixtures including lavender, citronella, orange and peanut, almond, sunflower, and soy seed oils were analyzed. The results showed that the efficacy of this approach does not depend on the specific combination of EO and vegetable oil, ensuring its versatility. The method was able to determine the adulterant, with a mean accuracy of 91.81 and 89.77% for calculations made on ¹H and ¹³C spectra, respectively. The high precision and accuracy here observed, make ¹H-qNMR competitive with other well-established techniques. Considering the current importance of quality control of EOs to avoid fraudulent practices, this work can be considered pioneering and promising.     

119Sn Mössbauer characterization of self assembled organotin(IV) complexes with Schiff bases containing amino acetate skeletons

Several organotin(IV) compounds, viz., diorganotin(IV) compounds of the types Ph₂SnLH (monomer), ⁿBu₂SnLH·OH₂ (monomer), [Me₂SnLH·OH₂]₂ (centrosymmetric dimer), [ⁿBu₂SnLH]₃ (cyclic trinuclear), [Ph₂SnLH] _n (polymer), {[ⁿBu₂Sn(LH)]₂O}₂ (centrosymmetric tetranuclear), dinuclear di-/tri-mixed organotin(IV) compounds Ph₂SnLH·Ph₃SnCl (monomer) and triorganotin(IV) compounds of the types [Bz₃SnLH]₂ (centrosymmetric dimer) and [Me₃SnL¹H] _n (Polymer) (LH = Schiff base carboxylate) have been studied in the solid state at liquid nitrogen temperature using ¹¹⁹Sn Mössbauer spectroscopy. The tin coordination geometry of the compounds determined from crystallography was correlated with the ¹¹⁹Sn Mössbauer results.     

Metabolic Studies of Tumor Cells Using [1-13C] Pyruvate Hyperpolarized by Means of PHIP-Side Arm Hydrogenation

The kinetics of metabolic processes can be assessed, in real time by means of MR hyperpolarized (HP) metabolites. [1-¹³C]pyruvate, hyperpolarized by means of d-DNP, is, by far, the substrate most widely applied to the investigation of several pathologies characterized by deregulated glycolytic metabolic networks, including cancer. Hyperpolarization of [1-¹³C]pyruvate by means of the cost effective, fast and easy to handle PHIP-SAH (para-hydrogen induced polarization-side arm hydrogenation) method opens-up a pathway for the application of HP metabolites to a wide range of cancer-related studies. Herein, we report the first application of PHIP-SAH hyperpolarized [1-¹³C]pyruvate in the investigation of upregulated glycolysis in two murine breast cancer cell lines (168FARN and 4T1). The results obtained using HP pyruvate have been validated with a conventional biochemical assay and are coherent with previously-reported lactate dehydrogenase activity measured in those cells.     

Effect of the Joule heating and of the material voids on free-convective transport in porous or fibrous media with applied electrical fields

The effect of the geometry of the soil in electrokinetic application has been studied by using capillary models of annular geometry. The Joule heating generation has been included as a primary effect of temperature development leading to buoyancy flows. The heat transfer model has been formulated for conduction-dominated regime. The results of this model have been coupled with the motion equation to obtain the analytical hydrodynamic velocity profile. Numerical illustrations, demonstrating the effect of the cross-sectional area of the annular region on the velocity field, have been included. It is observed that a substantial effect on the magnitude of such velocity field for different parameters of the system. The results are useful to obtain better understanding of the role of the soil geometry in potential soil cleaning field operations.     

Intramolecular Diels-Alder reactions of N-substituted oxazolones

The first intramolecular Diels-Alder reactions of simple trienes featuring an N-substituted oxazolone as the dienophilic component have been investigated and are reported herein.     

Dipole moments of organophosphorus compounds

Russian Chemical Bulletin -     

Finite Pluricomplex Energy Measures

We investigate probability measures with finite pluricomplex energy. We give criteria insuring that a given measure has finite energy and test these on various examples. We show that this notion is a biholomorphic but not a bimeromorphic invariant.     

Solid‐State Conformational Flexibility at Work: Zipping and Unzipping within a Cyclic Peptoid Single Crystal

A peptidomimetic compound undergoes a reversible single‐crystal‐to‐single‐crystal transformation upon guest release/uptake with the transformation involving a drastic conformational change. The extensive and reversible alteration in the solid state is connected to the formation of an unprecedented “CH–π zipper” which can reversibly open and close (through the formation of CH–π interactions), thus allowing for guest sensing.