Publisher SummaryThis chapter discusses the biological activity of carbonyl difluoride (COF2). Carbonyl difluoride has a lower toxicological activity than phosgene owing to the greater stability of the C–F bond relative to C–Cl. The effects of carbonyl difluoride on the respiratory system are ...

In this study, we demonstrated the usefulness of proton conducting electrolytes (such as ammonium thiocyanate (NH4SCN) and ammonium nitrate (NH4NO3)) for electrochemical energy storage devices using activated carbon (AC) as the electrode material. The cyclic voltammetry analysis revealed the pre...

The crystal of [C6H13N2]+[HF2]− is built of ionic pairs tied by strong N–H···F hydrogen bonds. A very strong F–H···F hydrogen bond linking the anion is symmetric at higher temperatures, while upon cooling the H-atom shifts continuously to a clearly non-centred site. This first observatio...

[18F]Xenon difluoride ([18F]XeF2), was produced by treating xenon difluoride with cyclotron-produced [18F]fluoride ion to provide a potentially useful agent for labeling novel radiotracers with fluorine-18 (t1/2 = 109.7 min) for imaging applications with positron emission tomography. Firstly, th...

In the presented work we systematically study the influence of phosphoric acid, ammonium trifluoromethanesulfonate (ATFMS), and polyvinylidene difluoride (PVDF) on the oxygen reduction reaction (ORR) activity of carbon supported, Pt based catalysts. The influence of phosphoric acid is investigat...

The fluorination reactions of natural sulfides with ammonium hydrogen difluoride (NH4HF2) were studied. It was established that nonstoichiometric ammonium fluoroferrates are formed by interaction of pyrrhotite with NH4HF2. Their composition depends on the access of oxygen. Fe(II) is responsible ...

The present study aims to investigate the fluorination of thorium oxide (ThO2) by ammonium hydrogen difluoride (NH4HF2). Fluorination was performed at room temperature by mixing ThO2 and NH4HF2 at different molar ratios, which was then left to react for 20 days. Next, the mixtures were analyzed ...

Brønsted acids induced the intramolecular cyclisation of 3-aryloxypropanoic esters affording 3-methyl-4-chromanones, which have been transformed into the corresponding racemic benzyl β-oxoesters. These latter esters, in the presence of hydrogen and catalytic amounts of both palladium and (endo,...

Seven new 2,3-dimethoxy-3-hydroxy-2-(1-phenyl-3-aryl-4-pyrazolyl)chromanones (5) have been synthesized by the oxidation of 3-hydroxy-2-(1-phenyl-3-aryl-4-pyrazolyl)chromones (4) with iodobenzene diacetate in methanol. The structures of compounds 5 were established by the combined use of 1H NMR, ...

2-Substituted 4-chromanones were synthesized in their optically active forms. The chiral intermediates were obtained via lipase-catalyzed enantioselective reactions. Lipase and esterase were also used for the hydrolysis of ester moieties of the precursors of the target compounds under mild condi...

An efficient and simple route to biologically and pharmaceutically important o-hydroxyaryl ketones, xanthones, 4-chromanones, and flavones has been developed utilizing readily available carboxylic acids and commercially available o-(trimethylsilyl)aryl triflates.

Ledebouria revoluta (Hyacinthaceae: Hyacinthoideae), used widely as an ethnomedicinal in southern Africa, has been characterised phytochemically for the first time. Four homoisoflavanones (3-benzyl-4-chromanones) were isolated from the bulbs and their absolute configuration at C-3 determined usi...

Halogen substituent plays an important role in the crystalline packing of aromatic compounds. The [2+2] photocycloaddition of (E)-3-benzylidene-4-chromanones in the crystalline state was investigated, and halogen substitution has been adopted to organize molecules with proper arrangement for pho...

A two step efficient and practical synthesis of a variety of 4-chromanones is described. Phenols undergo a Michael addition to acrylonitriles in the presence of catalytic amounts of potassium carbonate and tert-butanol to generate the corresponding 3-aryloxypropanenitriles in 50–93% yields. Tre...

An efficient tandem reaction approach is described to prepare 4-chromanones from electron-rich phenols and 3,3-dimethylacrylic acid or trans-crotonic acid in boiling toluene using 20 mol % bismuth(III) triflate as the catalyst. The reaction is also successful from the corresponding aryl esters o...

Biotransformation of 4-chromanone and its derivatives in the cultures of three biocatalysts: Didymosphaeria igniaria, Coryneum betulinum and Chaetomium sp. is presented. The biocatalysts were chosen due to their capability of enantiospecific reduction of low-molecular-weight ketones (acetophenon...

SummaryWhile mitochondrial dysfunction is emerging as key in Parkinson’s disease (PD), a central question remains whether mitochondria are actual disease drivers and whether boosting mitochondrial biogenesis and function ameliorates pathology. We address these questions using patient-derived in...

BackgroundNicotinamide riboside (NR) is a nicotinamide adenine dinucleotide (NAD+) precursor which is present in foods such as milk and beer. It was reported that NR can prevent obesity, increase longevity, and promote liver regeneration. However, whether NR can prevent ethanol-induced liver inj...

SummaryConditions of metabolic stress dysregulate the NAD metabolome. By restoring NAD, nicotinamide riboside (NR) provides resistance to such conditions. We tested the hypotheses that postpartum might dysregulate maternal NAD and that increasing systemic NAD with NR might benefit mothers and of...

SummaryIt has been recently shown that increased oxidative phosphorylation, as reflected by increased mitochondrial activity, together with impairment of the mitochondrial stress response, can severely compromise hematopoietic stem cell (HSC) regeneration. Here we show that the NAD+-boosting age...