Peptide production method comprising step for translating amino acid having oxygen atom at specific position

A method for producing a peptide, comprising a step of translating a nucleic acid that comprises a codon encoding a first unnatural amino acid and a codon encoding a second unnatural amino acid which are adjacent to each other, wherein

• at least one of the first unnatural amino acid and the second unnatural amino acid is an unnatural amino acid U1, and the unnatural amino acid U1 is an unnatural amino acid that meets the following requirement (A) and meets at least one selected from the group consisting of the following requirements (B) and (C):
• (A) a nitrogen atom constituting a main-chain amino group (nitrogen atom N1) and an oxygen atom other than an oxygen atom constituting a main-chain carboxy group (oxygen atom O1) are bound via two atoms to each other;
• (B) the oxygen atom O1 constitutes an alkoxy group or an aryloxy group;
• (C) the nitrogen atom N1 is bound to a linear or branched C1-C6 alkyl group.

A method for producing a peptide, comprising a step of translating a nucleic acid that comprises a codon encoding a first unnatural amino acid and a codon encoding a second unnatural amino acid which are adjacent to each other, wherein

• at least one of the first unnatural amino acid and the second unnatural amino acid is an unnatural amino acid U1, and the unnatural amino acid U1 is an unnatural amino acid represented by the following formula (I):
• wherein n is an integer of 0 or more and 2 or less;
• R1 is a group represented by formula (II), a hydrogen atom or a linear or branched C1-C6 alkyl group;
• R2 and R3 are each independently (a) a group represented by the formula (II), (b) a hydrogen atom, or (c) a linear or branched C1-C4 alkyl group;
• R2b and R3b are each independently a hydrogen atom or a linear or branched C1-C4 alkyl group;
• R2 and R2b or R3 and R3b may form a ring together with a carbon atom to which they are bound;
• any one or more of R1, R2, and R3 is a group represented by the formula (II);
• N1 (nitrogen atom N1) in the formula (I) and O1 (oxygen atom O1) in the formula (II) are bound via two atoms to each other;
• when R1 is a substituent represented by the formula (II), R4 and R2 may form a ring together with a carbon atom to which R2 is bound and N1;
• when a plurality of R3 is present, they are each independently the same as or different from each other;
• when a plurality of R3b is present, they are each independently the same as or different from each other;
• in the formula (II),
• represents a binding position with N1;
• R4 is a C1-C2 alkylene group;
• R5 is a hydrogen atom, a linear or branched C1-C6 alkyl group, a C3-C10 cycloalkyl group, a C6-C10 aryl group, a C7-C12 arylalkyl group, or a C7-C12 alkylaryl group;
• and
• when R2 is a substituent represented by the formula (II), at least one of R1 in the formula (I) and R5 in the formula (II) is not a hydrogen atom.