Abstract: An object of the present invention is to provide methods of discovering drugs effective for tough targets, which have conventionally been discovered only with difficulty. The present invention relates to novel methods for cyclizing peptide compounds, and novel peptide compounds and libraries comprising the same, to achieve the above object.

Abstract: Methods of producing a peptide containing an N-substituted amino acid or N-substituted amino acid analog of the present invention include the steps of: preparing an Fmoc-protected amino acid, an Fmoc-protected amino acid analog, or an Fmoc-protected peptide; deprotecting a protecting group which have an Fmoc skeleton of the Fmoc-protected amino acid and such by using a base; and forming an amide bond by adding a new Fmoc-protected amino acid and such; and when the peptide is produced by a solid-phase method, the obtained peptide is cleaved off from the solid phase under conditions of weaker acidity than TFA. Furthermore, at least one side chain of the obtained peptide has a protecting group that is not deprotected under basic conditions and is deprotected under conditions of weaker acidity than TFA.

Abstract: Methods of producing a peptide containing an N-substituted amino acid or N-substituted amino acid analog of the present invention include the steps of: preparing an Fmoc-protected amino acid, an Fmoc-protected amino acid analog, or an Fmoc-protected peptide; deprotecting a protecting group which have an Fmoc skeleton of the Fmoc-protected amino acid and such by using a base; and forming an amide bond by adding a new Fmoc-protected amino acid and such; and when the peptide is produced by a solid-phase method, the obtained peptide is cleaved off from the solid phase under conditions of weaker acidity than TFA. Furthermore, at least one side chain of the obtained peptide has a protecting group that is not deprotected under basic conditions and is deprotected under conditions of weaker acidity than TFA.

Abstract: The present inventors found cyclic peptide compounds that interact with Ras, and non-natural amino acids useful for the production of the cyclic peptide compounds. The inventors also found that the cyclic peptide compounds inhibit the binding between Ras and SOS. In addition, the inventors found specific non-natural amino acids contained in the cyclic peptide compounds and methods for production thereof.

Abstract: Methods of producing a peptide containing an N-substituted amino acid or N-substituted amino acid analog of the present invention include the steps of: preparing an Fmoc-protected amino acid, an Fmoc-protected amino acid analog, or an Fmoc-protected peptide; deprotecting a protecting group which have an Fmoc skeleton of the Fmoc-protected amino acid and such by using a base; and forming an amide bond by adding a new Fmoc-protected amino acid and such; and when the peptide is produced by a solid-phase method, the obtained peptide is cleaved off from the solid phase under conditions of weaker acidity than TFA. Furthermore, at least one side chain of the obtained peptide has a protecting group that is not deprotected under basic conditions and is deprotected under conditions of weaker acidity than TFA.

Abstract: Methods of producing a peptide containing an N-substituted amino acid or N-substituted amino acid analog of the present invention include the steps of: preparing an Fmoc-protected amino acid, an Fmoc-protected amino acid analog, or an Fmoc-protected peptide; deprotecting a protecting group which have an Fmoc skeleton of the Fmoc-protected amino acid and such by using a base; and forming an amide bond by adding a new Fmoc-protected amino acid and such; and when the peptide is produced by a solid-phase method, the obtained peptide is cleaved off from the solid phase under conditions of weaker acidity than TFA. Furthermore, at least one side chain of the obtained peptide has a protecting group that is not deprotected under basic conditions and is deprotected under conditions of weaker acidity than TFA.

Abstract: An object of the present invention is to provide methods of discovering drugs effective for tough targets, which have conventionally been discovered only with difficulty. The present invention relates to novel methods for cyclizing peptide compounds, and novel peptide compounds and libraries comprising the same, to achieve the above object.

Abstract: Methods of producing a peptide containing an N-substituted amino acid or N-substituted amino acid analog of the present invention include the steps of: preparing an Fmoc-protected amino acid, an Fmoc-protected amino acid analog, or an Fmoc-protected peptide; deprotecting a protecting group which have an Fmoc skeleton of the Fmoc-protected amino acid and such by using a base; and forming an amide bond by adding a new Fmoc-protected amino acid and such; and when the peptide is produced by a solid-phase method, the obtained peptide is cleaved off from the solid phase under conditions of weaker acidity than TFA. Furthermore, at least one side chain of the obtained peptide has a protecting group that is not deprotected under basic conditions and is deprotected under conditions of weaker acidity than TFA.

Abstract: The present inventors have found that when screening for cyclic peptide compounds that can specifically bind to a target molecule, the use of a library including cyclic peptide compounds having a long side chain in the cyclic portion can improve the hit rate for cyclic peptide compounds that can specifically bind to the target molecule. Meanwhile, the present inventors have found that tryptophan and tyrosine residues, which have conventionally been used in oral low molecular-weight pharmaceuticals and are amino acid residues having an indole skeleton or a hydroxyphenyl group, are not suitable for peptides intended to attain high membrane permeability.

Abstract: An object of the present invention is to provide methods of discovering drugs effective for tough targets, which have conventionally been discovered only with difficulty. The present invention relates to novel methods for cyclizing peptide compounds, and novel peptide compounds and libraries comprising the same, to achieve the above object.

Abstract: An object of the present invention is to provide methods of discovering drugs effective for tough targets, which have conventionally been discovered only with difficulty. The present invention relates to novel methods for cyclizing peptide compounds, and novel peptide compounds and libraries comprising the same, to achieve the above object.

Abstract: An object of the present invention is to provide methods of discovering drugs effective for tough targets, which have conventionally been discovered only with difficulty. The present invention relates to novel methods for cyclizing peptide compounds, and novel peptide compounds and libraries comprising the same, to achieve the above object.