Cyclic peptide cyclized in aromatic nucleophilic substitution reaction, and peptide library, production method, and screening method for same

A peptide compound having a cyclic moiety,

• wherein the cyclic moiety has:
• a benzoic acid derivative;
• and
• a peptide backbone,
• the peptide backbone has a thiol group-containing residue,
• the benzoic acid derivative linker is bound to the peptide backbone via an N-terminal amino acid residue of the peptide backbone and the thiol group-containing residue, and
• the benzoic acid derivative linker is a compound represented by the following chemical formula (I):
• [Chemistry 2]
• (in the chemical formula (I),
• R1, R2, R3 and R4 are independently —F, —H, —Cl, —Br, —SO2NH2, —CF3, —SO2CH3 or —NO2, respectively,
• a wave line 1 represents a covalent bond with the N-terminal amino acid residue of the peptide backbone, and
• a wave line 2 represents a covalent bond with the thiol group-containing residue in the peptide backbone).

An initiator tRNA having a fluorobenzoic acid derivative linker precursor represented by the following chemical formula (IV):

• [Chemistry 5]
• (In the chemical formula (IV),
• R5, R6, R7 and R5 are independently —F, —H, —Cl, —Br, —SO2NH2, —CF3, —SO2CH3 or —NO2, respectively, and
• a wave line 3 represents a covalent bond with tRNA).