Cytotoxicity of new secondary metabolites,fatty acids and tocols composition of seeds of Ducrosia anethifolia (DC.) Boiss

Two new monoterpene Ducrosin A (1) and sesquiterpene Ducrosin B (2) were isolated along with three known compounds, stigmasterol (3) and two furanocoumarins (4 and 5), from the dichloromethane extract of the seeds of Ducrosia anethifolia (DC.) Boiss. Their structures were determined using extensive 1D and 2D NMR, (ES)-HRMS and IR spectroscopic analyses and by comparison with literature data. Gas chromatography analysis of the fatty acids (FAs) of D. anethifolia seed oils (DAOs) showed high percentages of elaidic acid (C18:1 Δ9t) 65% and oleic acid (C18:1 Δ9c) 15%. The total tocopherol (tocols) content in DAOs was found to be 164 mg/100 g. The cytotoxic effect of the isolates was also evaluated using the MTT assay against the HCT-116 and SKOV-3 cell lines. The results showed that compound 2 was the most cytotoxic agent followed by compounds 1 and 4, which has an epoxide moiety that most likely contributes to its activity.     

Reaction of 5-aminotetrazole with vinamidinium salts: Formation of 2-(N, N-dimethylamino)-5-substituted pyrimidines

The cyclocondensation of vinamidinium salts with 5-aminotetrazole in basic media affords regiospecifically good yields of 2-(N, N-dimethylamino)-5- aryl-, arylsulfonyl- and 2-(N, N-dimethylamino)-5-formyl-pyrimidines, respectively.     

Robust and high-order effective boundary conditions for perfectly conducting scatterers coated by a thin dielectric layer

A new approach is considered to construct effective boundaryconditions for the solution of problems related to the scatteringof electromagnetic waves by perfectly conducting cylinders coatedby a thin dielectric shell. These boundary conditions aim tobe both robust and of high order while remaining set in termsof surface differential operators involving at most second-orderderivatives. Error estimates yield a theoretical basis for theuse of these boundary conditions in practical computations.Some numerical experiments at frequencies beyond the range ofvalidity of the usual impedance boundary conditions validatethe efficiency of the approach.     

Über die Einwirkung des Bromwasserstoffs und der Schwefelsäure auf primäre Alkohole

Ohne Zusammenfassung     

Influence of anion substitution on hydrogen‐bonding patterns of salt compounds: cytosinium hydrogen sulfate and cytosinium perchlorate

In the two title compounds, cytosinium hydrogen sulfate, C₄H₆N₃O⁺·HSO₄⁻, (I), and cytosinium perchlorate, C₄H₆N₃O⁺·ClO₄⁻, (II), the asymmetric units comprise a cytosinium cation with hydrogen sulfate and perchlorate anions, respectively. The crystal structures of (I) and (II) are similar; that of (I) is characterized by a three‐dimensional N—H...O, O—H...O and C—H...O hydrogen‐bonded network. In (I) and (II), two‐dimensional layers are formed by N—H...O and C—H...O hydrogen bonds and, in the case of (I), they are linked by O—H...O hydrogen bonds where the anion acts as a donor and the cation as an acceptor. The hydrogen‐bonded sheets in (II) form an angle of 87.1°.     

SFG study of the ethanol in an acidic medium--Pt(110) interface: effects of the alcohol concentration

Ethanol in an acidic solution-Pt(110) interface was studied by SFG spectroscopy (between 1820 and 2325 cm(-1)) to explore primarily the effects of the alcohol concentration. Stretching bands of H-Pt (ca. 1970 or 2050 cm(-1)) and CO (ca. 1980 and 2040 cm(-1)) species, produced by the ethanol oxidation, were detected during the adsorption and oxidation of 0-1 mol L(-1) ethanol in a 0.1 mol L(-1) HClO(4) solution on the electrode surface. Hydrogen and CO coadsorb stably on Pt(110) between 0.05 and 0.15 V in ethanol-containing solutions. In this potential range, the blue shift of the hydrogen resonance (ca. 80 cm(-1)) reveals a weakening of the hydrogen bonding between adsorbed hydrogen and water molecules in the double layer. After the hydrogen desorption (0.15 V), the formation of compact CO islands, depending on the ethanol concentration, lifts the Pt(110) surface reconstruction. In ethanol-free solution, the surface remains reconstructed. The lower-frequency CO band is assigned to the CO species adsorbed on (1 x 2) reconstructed Pt(110) domains, having smaller local coverages, while the higher-frequency CO band is attributed to the close-packed CO species adsorbed on (1 x 1) patches. The reaction pathway forming CO(2) is less favored with increasing ethanol concentration.     

Über die Einwirkung der Reductionsmittel auf Cholsäure

Ohne Zusammenfassung     

Galerkin method for nonlocal mixed boundary value problem for the Moore‐Gibson‐Thompson equation with integral condition

In this paper, we are going to deal with the nonlocal mixed boundary value problem for the Moore‐Gibson‐Thompson equation. Galerkin method was the main used tool for proving the solvability of the given nonlocal problem.