Abstract: The present disclosure provides a method of producing bivalirudin using a peptide fragment or peptide fragments on solid phase peptide synthesis that minimizes, or eliminates, the production of bivalirudin molecules having too few or too many glycine residues.

Abstract: The invention provides processes of purifying a peptide including a GCC agonist sequence selected from the group consisting of SEQ ID NOs: 1-251 described herein. The processes include a solvent exchange step before a freeze-drying (lyophilization) step.

Abstract: The invention provides processes of preparing a peptide including a GCC agonist sequence selected from the group consisting of SEQ ID NOs: 1-249 described herein.

Abstract: A method for preparing exenatide by solid-phase synthesis, including: 1) mixing an Fmoc-Rink amide AM resin with a deprotecting agent to obtain a Rink amide AM resin; 2) condensing an Fmoc-Ser(tBu)-OH with the Rink amide AM resin to obtain an Fmoc-Ser(tBu)-Rink amide AM resin; 3) repeating the Fmoc deprotection and the condensation between an amino acid and a polypeptide on the resin, and condensing an amino acid with a polypeptide on the resin from the C-terminal to the N-terminal, to form a polypeptide resin; and 4) separating the polypeptide and the resin on the polypeptide resin.

Abstract: A method for producing bivalirudin using solid phase peptide synthesis by: a) condensing Fmoc-Asn(Trt)-Gly-OH with a peptide resin of Asp(OtBu)11-Phe12-Glu(OtBu)13-Glu(OtBu)14-Ile15-Pro16-Glu(OtBu)17-Glu(OtBu)18-Tyr(tBu)19-Leu20-Resin; b) removing Fmoc-; c) condensing Fmoc-Gly-Gly-Gly-Gly-OH with the peptide resin; d) separately condensing Pro, Arg, Pro, and Phe with the peptide resin from C-terminal to N-terminal to yield a peptide resin of Boc-D-Phe1-Pro2-Arg(Pbf)3-Pro4-Gly5-Gly6-Gly7-Gly8-Asn(Trt)9-Gly10-Asp(OtBu)11-Phe12-Glu(OtBu)13-Glu(OtBu)14-Ile15-Pro16-Glu(OtBu)17-Glu(OtBu)18-Tyr(tBu)19-Leu20-Resin; and e) in the presence of a cleavage agent, separating a peptide from the peptide resin to yield bivalirudin represented by Formula VI. The method is low in cost and the resultant bivalirudin has high purity.

Abstract: A method for producing bivalirudin using solid phase peptide synthesis by the following steps: a) mixing a Fmoc-amino acid resin or a Fmoc-peptide resin with a de-protective agent so as to remove Fmoc-; b) in the presence of a condensing agent, condensing a Fmoc- or Boc-amino acid with the amino acid or the peptide bound to the resin; c) repeating the steps a) and b) to yield a peptide resin represented by Formula I, (SEQ?ID?NO.?1) Boc-D-Phe1-Pro2-Arg(Pbf)3-Pro4-Gly5-Gly6-Gly7- Gly8-Asn(Trt)9-Gly10-Asp(OtBu)11-Phe12-Glu (OtBu)13-Glu(OtBu)14-Ile15-Pro16-Glu(OtBu)17-Glu (OtBu)18-Tyr(tBu)19-Leu20-Resin?(I) and d) in the presence of a cleavage agent, separating the peptide from the resin to yield bivalirudin represented by Formula II (SEQ ID NO. 2). D-Phe-Pro-Arg-Pro-Gly-Gly-Gly-Gly-Asn-Gly-Asp-Phe- Glu-Glu-Ile-Pro-Glu-Glu-Tyr-Leu?(II) Based on its total volume, the de-protective agent is composed of between 3 and 20% of piperidine and between 0.