LC/MS/MS analysis of α‐tocopherol and coenzyme Q10 content in lyophilized royal jelly,beebread and drone homogenate

This study shows the results of application liquid chromatography‐tandem mass spectrometry (LC/MS/MS) for assay of the content of α‐tocopherol and coenzyme Q₁₀ in bee products of animal origin, i.e. royal jelly, beebread and drone homogenate. The biological matrix was removed using extraction with n‐hexane. It was found that drone homogenate is a rich source of coenzyme Q₁₀. It contains only 8 ± 1 µg/g of α‐tocopherol and 20 ± 2 µg/g of coenzyme Q₁₀. The contents of assayed compounds in royal jelly were 16 ± 3 and 8 ± 0.2 µg/g of α‐tocopherol and coenzyme Q₁₀, respectively. Beebread appeared to be the richest of α‐tocopherol. Its level was 80 ± 30 µg/g, while the level of coenzyme Q₁₀ was only 11.5 ± 0.3 µg/g. Copyright © 2016 John Wiley & Sons, Ltd.     

Systems biology reveals biology of systems

In the last decades, genomic and postgenomic technologies obtained a great amount of information on molecular bases of cell physiology and organization. In spite of this, the knowledge of cells and living organisms in their entirety, is far from being achieved. In order to deal with biological complexity, Systems Biology uses a new approach to overcome this inadequacy. Despite different definitions, Systems Biology's view of biological phenomena highlights that a holistic perspective is needed to integrate and understand the huge amount of empirical data which have been collected. This is one of the aspects that makes Systems Biology so interesting, from a theoretical and epistemological point of view, and that renders it a useful tool to help students approach living beings' dynamics within a comprehensive framework of their biological features as well. © 2010 Wiley Periodicals, Inc. Complexity, 2010     

Electrochemical Studies of CO2-Reducing Metalloenzymes

Only two enzymes are capable of directly reducing CO₂: CO dehydrogenase, which produces CO at a [NiFe₄S₄] active site, and formate dehydrogenase, which produces formate at a mononuclear W or Mo active site. Both metalloenzymes are very rapid, energy-efficient and specific in terms of product. They have been connected to electrodes with two different objectives. A series of studies used protein film electrochemistry to learn about different aspects of the mechanism of these enzymes (reactivity with substrates, inhibitors…). Another series focused on taking advantage of the catalytic performance of these enzymes to build biotechnological devices, from CO₂-reducing electrodes to full photochemical devices performing artificial photosynthesis. Here, we review all these works.     

Magnetic fluid poly(ethylene glycol) with moderate anticancer activity

Poly(ethylene glycol) (PEG)-containing magnetic fluids - magnetite (Fe₃O₄) stabilized by sodium oleate - were prepared. Magnetic measurements confirmed superparamagnetic behaviour at room temperature. The structure of that kind of magnetic fluid was characterized using different techniques, including electron microscopy, photon cross correlation spectroscopy and small-angle neutron scattering, while the adsorption of PEG on magnetic particles was analyzed by differential scanning calorimetry and Fourier transform infrared spectroscopy. From the in vitro toxicity tests it was found that a magnetic fluid containing PEG (MFPEG) partially inhibited the growth of cancerous B16 cells at the highest tested dose (2.1 mg/ml of Fe₃O₄ in MFPEG).     

Productive trapping of NAD-type radicals. Non-biomimetic reduction of pyridinium salts

One-electron reduction of pyridinium salts (NAD+ analogues) generates dihydropyridyl radicals which may then be engaged in radical addition processes to regioselectively form gamma-substituted dihydropyridines.     

Coordination number of percolating clusters

The coordination number of percolating clusters and their backbones, on the square and simple cubic lattices, is investigated numerically. At the percolation threshold, the average coordination number of the clusters is 2.239 ± 0.012 and 2.079 ± 0.016 for d = 2 and d = 3, respectively. The corresponding numbers for the backbones are 2.402 ± 0.016 and 2.246 ± 0.034.     

2-Methoxy-6-oxo-1,4,5,6-tetrahydropyridine-3-carbonitriles: versatile starting materials for the synthesis of libraries with diverse heterocyclic scaffolds

Heterocyclic demonstration libraries for agrochemical screening were prepared from the common intermediates 2-methoxy-6-oxo-1,4,5,6-tetrahydropyridine-3-carbonitriles (1), using standard solution-phase techniques. A total of 18 screening libraries were prepared in good to excellent yields. Several members of these libraries were active in the first level of agrochemical screening, especially in the fungicide screen.     

Tandem radical addition and cyclization of epsilon-substituted delta-yne ketimines

The first one-step conversions of ketimines I into cyclized allylamine derivatives of types II and III are reported.