Hoechst Aktiengesellschaft

Behringwerke Aktiengesellschaft

Rainer Uhmann

Volker Teetz

Hans-Jerg Kleiner

Rolf Geiger

Gunter Roscher

Hermann Erich Karges

Harald Berger

Dirk Bottger

Manfred Schmidt

Helmut Heber

Kurt Radscheit

Rudolf Knapp

Process for the preparation of pure propanephosphonic anhydride, which comprises distilling crude, impure propanephosphonic anhydride having an average degree of polymerization of 20 to 200 and containing less than 0.5% by weight of water by heating to 230 to 300.degree. C. under a pressure of 0.1 to 100 mbar, pure propanephosphonic anhydride having an average degree of polymerization of 20 to 60 being obtained.

Process for the preparation of pure propanephosphonic anhydride

The invention relates to a process for the preparation of peptides of the formula I

Process for the low-racemization preparation of peptide intermediates of

What are disclosed are chromogenic peptides useful as substrates for the detection and determination of enzymes having a hydrolytic action and methods for detecting and determining enzymes with such peptides.

Chromogenic compounds and their use as enzyme substrates

In this chromatograph for pressure chromatography, a plunger having a plunger stem is arranged so that it can move within the separation column (3). On the front face of the plunger there is a collecting space (7) for liquid, which is covered by a frit (6) and which has a connecting line (8) to the face of the plunger opposed to the front face. In order to prevent abrasive and chemical attack by the column packing on the plunger, its seal and the cylinder wall of the separation column, the plunger should comprise a lower part (2) having a device (4) to accommodate the plunger stem (5), and an upper part (1), the two parts being arranged so that they can move in relation to one another. The upper part (1) has a centering peg (9) which projects into the lower part (2). A spring (12) on which the upper part (1) is supported, is located concentrically in relation to the peg (9). The upper part (1) has recesses on its circumference to accommodate at least two seals (19 and 21) and a ring channel (16) which is formed by a retaining ring (13) for one seal (19) and is connected to the collecting space (7). The other seal (21) is held in its recess by a ring (23) which is located concentrically around the spring and is supported by the lower part.

Chromatograph for pressure chromatography

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Kriftel, Germany

Rainer Uhmann