Enantiomeric separations of remoxipride,propranolol, and trimipramine on CHIRAL-AGP using micellar chromatography and anionic additives

The retentions and enantiomeric resolutions of remoxipride, propranolol, and trimipramine were studied using a CHIRAL-AGP column with micellar mobile phases and aliphatic, anionic additives. The retentions of the compounds, which in neat buffer solution were very high (k′ > 50), could be decreased to k′ < 10 by adding a mixture of Tween® 20 and heptanoic acid to the mobile phase. The presence of the aliphatic acid was essential in order to increase the enantiomeric selectivity. An efficiency enhancement was obtained by increasing the temperature. With a mobile phase composition optimized for the separation of remoxipride, the possibility of detecting levels of the enantiomeric impurity (R-remoxipride) down to 0.025% in the drug was demonstrated. © 1993 Wiley-Liss, Inc.     

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Die Bedeutung vonDrosophila melanogaster für die genetische Forschung

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Adherence of bacteria to leaves.

Members of seven genra of bacteria, pathogens and nonpathogens of plants, adhered to young leaves when leaves were suspended in cell suspensions for 10 min. With Pseudomonas lachrymans, the adherence rate (cells applied vs. cells adhering) to host (cucumber) and nonhost (chrysanthemum) leaves was a straight-line, log-log function, as was the adherence of Escherichia coli and Serratia marcescens to cucumber leaves. Adhering cells of these three bacteria were washed with water from cucumber leaves at a straight-line, log-log rate. Adhered cells of P. lachrymans were most commonly found near veins on cucumber leaves. There appeared to be a polymeric surface layer on this bacterium on the cucumber leaf when leaves bearing bacteria were stained with ruthenium red and viewed in thin section.     

Effects of flue-curing and ageing on the volatile basic constituents of Virginia tobacco

Flue-curing and ageing of Virginia tobacco reduce the amounts of nicotine and several of its transformation products. In contrast, the concentrations of certain structurally simple pyridines and a few compounds, which are presumably products of sugar—amino acid interactions, are found to increase. Generation of several pyridines and a few other bases during the leaf processing is also observed.     

Farbfaktoren und Geschlechtsbestimmung

Ohne ZusammenfassungSoweit in der Arbeit keine neuen Tatsachen beigebracht werden, sei bezüglich der Literatur verwiesen aufKosswig, C.: Arch. Entw.mechan.128, 393–446 (1933).Die Berechtigung zur Verwendung des Symbolsz für das zum Heterochromosom des Platypoecilus homologe Chromosom ergibt sich aus den folgenden Absätzen.