CYCLIC PEPTIDE AND SERINE PROTEASE INHIBITOR

摘要

PROBLEM TO BE SOLVED: To obtain a cyclic peptide and a serine protease inhibitor. SOLUTION: This cyclic peptide is represented by the formula (X1 is Asp, Ala, Glu or Arg; X2 is Tyr, Trp or Phenol; A and B are the same or different and are each a direct bond or 1-13 α-amino acid residues; the total of amino acid residues of A and B is 0-13) or its salt.