Dorothee Wistuba

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When 1,3-butadiene is incubated with rat liver microsomes and NADPH both enantiomers of vinyl oxirane are formed, the amount of epoxide being dependent on incubation time, microsomal protein, and substrate concentration. Inhibition by SKF 525 A or dithiocarb as well as induction by pretreatment with phenobarbital or 20-methylcholanthrene suggest(More)
The enantioselectivity of the in vitro conversion of simple prochiral and chiral aliphatic alkenes into oxiranes by liver microsomes of untreated or induced (phenobarbital) rats, of untreated or induced (phenobarbital, benzo[a] pyrene) mice, and of humans was determined by complexation gas chromatography. The enantiomeric excess (ee) of the epoxides extends(More)
The in vitro conversion of chiral aliphatic monoalkylsubstituted oxiranes into 1,2-diols catalyzed by epoxide hydrolase of rat liver microsomes occurs with substrate enantioselectivity and regioselectivity. Substrate enantioselectivity is generally low, and has the same sense, for methyloxirane, vinyloxirane, epichloro-, and epibromohydrin. In the(More)
The stereoisomeric separation of several flavanones and flavanone-7-O-glycosides has been achieved with capillary electrophoresis by adding native cyclodextrins or cyclodextrin derivatives to the background electrolyte. As an alternative method, micellar electrokinetic chromatography with sodium cholate as a chiral surfactant has been used for the epimeric(More)
The stereoselectivity of the in vitro conversion of isoprene by liver enzymes of rats and mice was determined. Isoprene was epoxidized by cytochrome P450 of rats and mice to 2-isopropenyloxirane and 2-methyl-2-vinyloxirane with slight but different product enantioselectivity. Only with mouse liver microsomes was a distinct regioselectivity observed. Both(More)
Recent progress in enantiomeric separations by capillary electrochromatography (CEC) is reviewed. The development of simple and robust CEC column technologies plays an important role for popularization of CEC. During the last several years, various approaches for the preparation of enantioselective columns have been reported. Currently, the monolithic(More)
Enantiomer separation of chiral pharmaceuticals by capillary electrochromatography (CEC) is achieved with open-tubular capillaries (o-CEC), with packed capillaries (p-CEC) or with monolithic capillaries. In o-CEC, capillaries are coated with a thin film containing cyclodextrin derivatives, cellulose, proteins, poly-terguride or molecularly imprinted(More)
Chiral-modified silica-based monoliths have become well-established stationary phases for both high performance liquid chromatography (HPLC) and capillary electrochromatography (CEC). The silica-based monoliths were fabricated either in situ in the capillaries for nano-HPLC and CEC or in a mould for "conventional" HPLC. The present review summarizes the(More)
Lung surfactant mainly comprises phosphatidylcholines (PC), together with phosphatidylglycerols and surfactant proteins SP-A to SP-D. Dipalmitoyl-PC (PC16:0/16:0), palmitoylmyristoyl-PC (PC16:0/14:0), and palmitoylpalmitoleoyl-PC (PC16:0/16:1) together comprise 75-80% of surfactant PC. During alveolarization, which occurs postnatally in the rat, PC16:0/14:0(More)
Ltnα and Ltnβ are individual components of the two-peptide lantibiotic lacticin 3147 and are unusual in that, although ribosomally synthesized, they contain d-amino acids. These result from the dehydration of l-serine to dehydroalanine by LtnM and subsequent stereospecific hydrogenation to d-alanine by LtnJ. Homologues of LtnJ are rare but have been(More)