Abstract: 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.

Abstract: The invention relates to a process for the preparation of peptides of the formula IU--A.sup.1 --A.sup.2 13 A.sup.3 --A.sup.4 --A.sup.5 --X (I)in whichU denotes a urethane protective group,A.sup.1 denotes Trp or D-Trp,A.sup.2 denotes Ser, Ala or Thr,A.sup.3 denotes Tyr or Phe,A.sup.4 denotes Gly, the residue of a D-amino acid or the residue of a D-amino acid derivative,A.sup.5 denotes Leu, N-methyl-Leu, N-ethyl-Leu, Ser(Bu.sup.t), Cys(But), Asp(OBu.sup.t), Glu(OBu.sup.t), Orn(Boc) or Lys(Boc) andX denotes OBu.sup.t or A.sup.6 --Pro--Y,whereA.sup.6 represents Arg, Orn, Lys or homoarginine, andY represents Gly--NH.sub.2, NH--NH--CO--NH.sub.2, (C.sub.1 -C.sub.3)-alkylamino, cyclopropylamino, (C.sub.1 -C.sub.3)-alkylamino which is substituted with hydroxyl or fluorine, or cycloalkylamino which is substituted with hydroxyl or fluorine, using tripeptides of the formula II,U--A.sup.1 --A.sup.2 --A.sup.3 --OH,in which the residues are defined as above.

Abstract: 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.

Abstract: 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).