Ammonia → HCID 178455894, compound

Participants

Reaction Steps

370 mg of H-Pro-His-Pro-Phe-His-Sta-Ile-His-Lys-OMe×5 TFA are dissolved in 8 ml of H2O. The pH value is increased to 5.0 with 0.3N NH3, whereupon 40 μl of a 1% aqueous solution of trypsin are added and the pH value is maintained constant by means of a pH stat with the addition of 0.3N NH3. The absorption of base is complete after approximately 40 minutes. 1 ml of glacial acetic acid is added, the whole is heated for 2 minutes in a boiling water bath, concentrated to approximately 3 ml and lyophilised. The residue is dissolved in 3 ml of 0.05N AcOH, converted into the acetate by slowly being filtered through a column (φ=1 cm, length=10 cm) of weakly basic ion exchanger (Merck No. II) in acetate form, and the eluate is again lyophilised, yielding H-Pro-His-Pro-Phe-His-Sta-Ile-His-Lys-OH×AcOH in the form of amorphous white powder; Rf (D)=0.12; Rf (K)=0.14.

Provenance & Evidence