Cyclic peptide, affinity chromatography support, labeled antibody, antibody drug conjugate, and pharmaceutical preparation

A cyclic peptide represented by Formula (I),

• RN-Xg-[Xi-Xa-Xm-X1-X2-X3-Xn-Xb-Xj]k-Xh-RC (I):
• in Formula (I),
• RN represents an amino group, an amino group have undergone N-acetylation, an amino group have undergone N-formylation, or an amino group have undergone N-acylation;
• RC represents a carboxy group or a carboxy group have undergone amidation;
• X1 represents an L-leucine residue, an L-isoleucine residue, an L-methionine residue, an L-lysine residue, or an L-arginine residue;
• X2 represents an L-valine residue or an L-isoleucine residue;
• X3 represents an L-tryptophan residue;
• Xa is an amino acid residue selected from the group consisting of (2S)-2-amino-3-[(2-chloroacetyl)amino]propanoic acid residue, (2R)-2-amino-3-[(2-chloroacetyl)amino]propanoic acid residue, (2S)-2-amino-4-[(2-chloroacetyl)amino]butanoic acid residue, (2R)-2-amino-4-[(2-chloroacetyl)amino]butanoic acid residue, N-δ-chloroacetyl-L-ornithine residue, N-δ-chloroacetyl-D-ornithine residue, N-ε-chloroacetyl-L-lysine residue, and N-ε-chloroacetyl-D-lysine residue, Xb is an L-homocysteine residue or D-homocysteine residue, and Xa and Xb are bonded to each other through a thioether bond;
• Xg, Xh, Xi, Xj, Xm, and Xn each represent g consecutive X's, h consecutive X's, i consecutive X's, j consecutive X's, m consecutive X's, and n consecutive X's;
• X represents an amino acid residue, and in a case where there is a plurality of X's, the plurality of X's may be the same as or different from each other;
• g, h, i, and j each independently represent an integer equal to or greater than 0;
• m and n are integers satisfying 0≤m≤9, 0≤n≤9, and 3≤m+n≤9 simultaneously;
• and
• k is an integer equal to or greater than 1, and in a case where k≥2, X1, X2, X3, Xa, Xb, Xi, Xj, Xm, and Xn in a repeating unit [Xi-Xa-Xm-X1-X2-X3-Xn-Xb-Xj] each may be the same or different between the repeating units.