Péter Slégel

Displacement chromatography of oligomycins

Oligomycins A, B and C were separated by reversed-phase chromatography in the displacement mode on octadecylsilica columns. The carrier was a mixture of methanol and water and a saturated solution of palmitic acid in the carrier served as the displacer. The production rate was investigated as a function of the chromatographic conditions, i.e., methanol concentration in the carrier, displacer concentration, flow-rate and the amount and concentration of the oligomycin mixture in the feed solution. A practical guide for method development is given.

Chromatographic separation and molecular modelling of triazines with respect to their inhibition of the growth of L1210/R71 cells.

The potential anti-cancer activity of triazines was characterized by the inhibition of the growth of L1210/R71 cells. The retention times for fifteen triazine derivatives were measured by high-performance liquid chromatography on octyl silica and silica gel columns. The slope and intercept values of the plot of the logarithmic capacity factor versus acetonitrile concentration were calculated from the reversed-phase retention measurements. The adsorption properties of the compounds were characterized by the retention data obtained on silica gel columns using high and low concentrations of ammonium salts in the hydro-organic mobile phase. The non-polar, non-polar unsaturated and polar surface areas, the surface energies, the dipole moments and the Van der Waals radii of the molecules were calculated from their chemical structures after energy minimization on the basis of molecular mechanics. Correlation analysis of these parameters showed that the inhibitory effect is dependent on the polar and non-polar surface areas of the molecules. The reversed-phase slope showed a significant correlation with the difference between the accessible and the total non-polar surface areas of the compounds, whereas the intercept values correlated with the non-polar accessible surface area. The adsorption properties of the triazines on silica gel cannot be described by the molecular parameters investigated here.

Synthesis of 1′-Aryl-1,3′-bi-β-carbolines and Their Saturated Counterparts

ABSTRACT 1-Aryl-β-carboline-3-carbaldehyde building blocks have been used as the starting materials for the synthesis of novel bis-β-carboline derivatives. In the two-step synthesis the Pictet–Spengler reaction was used before the dehydrogenation of the polycyclic compound to the aromatic derivatives.

Synthesis of new tricyclic imidazotriazepine derivatives condensed with various heterocycles

Previously synthesized 9-aryl-5H-imidazo[2,1-d][1,2,5]triazepin-6(7H)-ones have been used as starting materials for the synthesis of three new tricyclic ring systems, where an imidazotriazepine is condensed with an imidazole, triazole or tetrazole ring. These novel compounds could be potential drug candidates for central nervous system diseases because of their closely related structure to known tricyclic derivatives with anticonvulsant activity.Graphical Abstract