Über das Verhalten des veratrumsauren Kalkes bei der trockenen Destillation

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Aus den Berichten der Commission für Erforschung des östlichen Mittelmeeres

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Über die Reactionsproducte von Benzylamin und Glycolchlorhydrin

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Über das Bergapten

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Verfahren zur Bestimmung des Stickstoffes in organischen Substanzen

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Über Ester von abnormer Structur

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Non-bilayer formation in the DPPE-DPPG vesicle system induced by deep rough mutant of Salmonella minnesota R595 lipopolysaccharide

The vesicle system consisting of 80 mol% dipalmitoylphosphatidylethanolamine (DPPE) and 20 mol% dipalmitoylphosphatidylglycerol (DPPG) undergoes to structural changes caused by various concentrations of Salmonella minnesota R595 lipopolysaccharide (LPS). The phenomenon was investigated by methods applying small- and wide-angle X-ray scattering (SAXS and WAXS), calorimetry (DSC) and freeze-fracture. In the low LPS concentration regime (investigated at 0.02 LPS/DPPE–DPPG molar ratio) a phase separation was observed. Two kind of domains are formed which are rich and poor in DPPE and in these domains cubic and lamellar structures are present, respectively. Increasing the LPS concentration up to 0.1 LPS/DPPE–DPPG molar ratio the phase separation is more expressed and the temperature domains of the phase transitions are more different. Increasing the temperature chain melting of the lamellar phase occurs first and destruction of the cubic phase is observed later. At high LPS concentration (equimolar ratio of LPS/DPPE–DPPG), where this amphiphilic molecule cannot be considered any more a guest molecule, the cubic structure dominates the phase behaviour of the LPS molecules.     

Comparison of betaine and l-stachydrine as phase-transfer catalysts in Michael addition and Darzens reaction

Betaine and l-stachydrine have been tested as phase-transfer catalysts in Michael and Darzens reactions. The catalytic effect of l-stachydrine was found comparable to that of betaine in Michael addition and even higher when considering Darzens reaction. The desired products have been obtained in higher yields in solid-liquid system than under liquid-liquid bi-phase conditions. The influence of microwave irradiation and ultrasound on the reaction rate has been studied.