Hoffmann-la Roche Inc.

Ernst Kupfer

Hans Iding

Steven Paul Hanlon

Stephan Doswald

Michelangelo Scalone

Ping Wang

Paul Hadvary

Beat Wirz

Kurt Puentener

Hans Lengsfeld

Bruno Lohri

Gerhard Steinbauer

Roumen Nikolaev Radinov

Erich Hochuli

Lianhe Shu

Erich Steinwender

Kazimierz Michal Pietrusiewicz

Ernst K Weibel

Wioleta Swierczynska

The present invention relates to biocatalytic asymmetric reduction for the preparation of 2-amino-[5-(1-hydroxy-2-hydroxy or halogen-ethyl)]-pyrazine derivatives of the formula wherein R is lower alkylcarbonyl or an amino protecting group and Ris hydroxy or halogen. The compounds are key intermediates in the manufacture of a glucokinase activator.

Biocatalytic asymmetric reduction in preparation of (S)-N-[5-(1,2-dihydroxy-ethyl)-pyrazinyl]-2,2-dimethyl-propionamide

The invention is concerned with new phosphine ligands of the formula I wherein

Phosphine ligands

The invention relates to a scalable biocatalytic process for the preparation of S-1,1,1-trifluoro-2-propanol with a enantiomeric excess of &#x3e;99% by asymmetric microbial reduction of 1,1,1-trifluoroacetone with Baker's yeast.

Asymmetric reduction of 1,1,1-trifluoroacetone

The present invention relates to a method for the purification of the lipstatin. Impurities are removed from a lipstatin preparation by: a) mixing the preparation with a polar phase and to form a first two phase system in which the ratio of the lipstatin to the non-polar impurities in the polar phase is greater than in the preparation, and separating the phases from the first two phase system and collecting the lipstatin-enriched polar phase, and b) i) diluting the lipstatin-enriched polar phase from step a) with water to form a diluted lipstatin-enriched polar phase containing the polar solvent in a percentage of at least seventy percent of the polar phase and lower than in the lipstatin-enriched polar phase from step a), and mixing the diluted lipstatin-enriched polar phase with a second non-polar phase, the second non-polar phase being the same non-polar solvent as the first non-polar phase in the same or greater relative amount to the polar phase as in the first two phase system; or ii) mixing the lipstatin-enriched polar phase from step a) with a second non-polar phase, the second non-polar phase being the same non-polar solvent as the first non-polar phase in a greater relative amount to the polar phase as in the first two phase system; to form a second two phase system in which the ratio of the lipstatin to the polar impurities in the second non-polar phase is greater than in the lipid-enriched polar phase from step a), and separating the phases from the second two phase system and collecting the lipstatin-enriched second non-polar phase.

Purification of lipstatin

Novel compounds of the formula ##STR1## wherein A signifies the group ##STR2## or --(CH.sub.2).sub.5 --, which inhibit pancreas lipase and can be used for the control or prevention of obesity and hyperlipaemia, are disclosed. The inventive compounds can be produced by the cultivation of microorganism Streptomyces toxytricini, identified as NRRL 15443.

Leucine derivatives

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Zurich, Switzerland

Ernst Kupfer