Abstract: Chiral selectors having ?-unsubstituted ?-amino acid derivatives of the structure: a stationary phase for separating substance mixtures containing the chiral selector, and processes for separating mixtures of chiral substances, including enantiomers, and especially enantiomers of substances selected from ?-amino acids and derivatives thereof, ?-amino acids and ?-hydroxy acids are provided.

Abstract: Chiral selectors having ?-unsubstituted ?-amino acid derivatives of the structure: a stationary phase for separating substance mixtures containing the chiral selector, and processes for separating mixtures of chiral substances, including enantiomers, and especially enantiomers of substances selected from ?-amino acids and derivatives thereof, ?-amino acids and ?-hydroxy acids are provided.

Abstract: The invention relates to a method for determining the isoform composition of erythropoietin, comprising the following steps: a) isoelectrical focusing of a sample comprising erythropoietin in a gel over a pH range having a lower limit of 2.5 to 3.5 and an upper limit of 5 to 8, wherein the sample comprising erythropoietin originates from a culture supernatant of erythropoietin producing eukaryotic cells; b) transferring of the proteins comprised and separated in the gel to a membrane; c) verifying the erythropoietin bound to the membrane by specific antibodies; and to a method for in-process control of culture supernatants of erythropoietin producing eukaryotic cells during the fermentative production process.

Abstract: Chiral selectors having ?-unsubstituted ?-amino acid derivatives of the structure: a stationary phase for separating substance mixtures containing the chiral selector, and processes for separating mixtures of chiral substances, including enantiomers, and especially enantiomers of substances selected from ?-amino acids and derivatives thereof, ?-amino acids and ?-hydroxy acids are provided.

Abstract: The present invention relates to a process for the fermentative continuous production of erythropoietin, where eukaryotic erythropoietin-producing cells are cultured in a perfusion reactor while retaining the cells, the glucose concentration in the culture supernatant being adjusted via the perfusion rate and the cell number via the cell retention rate and/or the outward transferal of defined amounts of cell-containing culture medium from the bioreactor within preset zones.

Abstract: The present invention relates to a method for preparing erythropoietin, wherein culture supernatant of erythropoietin-producing eukaryotic cells containing erythropoietin are subjected to the following steps: a) Removing the cell components; and b) treating the product from a) to the following chromatography steps in the sequence indicated i) reversed phase chromatography; ii) anion exchange chromatography; iii) hydroxyapatite chromatography.

Abstract: Chiral selectors having ?-unsubstituted ?-amino acid derivatives of the structure: a stationary phase for separating substance mixtures containing the chiral selector, and processes for separating mixtures of chiral substances, including enantiomers, and especially enantiomers of substances selected from ?-amino acids and derivatives thereof, ?-amino acids and ?-hydroxy acids are provided.

Abstract: The present invention relates to a process for the one-stage resalting and purification of oligopeptides. Oligopeptides are often not formed directly as acetates when synthesised. Acetate salts of oligopeptides are however desirable as bulk-active material for medical and formulation reasons. Processes known from the prior art have hitherto involved two separate steps or pyridine-containing solvents. The resalting and purification can be combined in one step and the use of pyridine as solvent can be avoided, if the oligopeptide in the form of its chloride salt is purified with an acetate-containing solvent by liquid chromatography methods.

Abstract: Acrolein polymer from acrolein and one or more polyhydric alcohols, characterized by release of monomeric acrolein in aqueous systems and hence by a prolonged effect on microorganisms, is prepared by adding acrolein to a reaction medium containing catalyst in dissolved form, and not allowing the temperature of the reaction medium to rise about 50.degree. C. The acrolein polymer may be used in aqueous systems as a biocide.