Polar Hinges as Functionalized Conformational Constraints in (Bi)cyclic Peptides

Area of Science:

• Medicinal Chemistry
• Organic Synthesis
• Peptide Chemistry

Background:

• Aqueous solubility is critical for peptide handling, purification, and biological activity.
• Existing peptide cyclization methods may not sufficiently enhance solubility.
• Novel chemical strategies are needed to improve the properties of cyclic peptides.

Purpose of the Study:

• To develop novel polar hinges for efficient peptide cyclization.
• To synthesize bicyclic and cyclized peptides with enhanced aqueous solubility and biological activity.
• To explore the utility of new triazine-based reagents for peptide modification.

Main Methods:

• Synthesis of two novel polar hinges: 1,1",1"-(1,3,5-triazinane-1,3,5-triyl)tris(2-bromoethanone) (TATB) and 2,4,6-tris(bromomethyl)-s-triazine (TBMT).
• One-step synthesis of TATB and TBMT from bromoacetonitrile.
• Application of TATB and TBMT derivatives for the preparation of bicyclic and cyclized peptides, including azide-modified versions for scaffold incorporation.

Main Results:

• TATB and TBMT were successfully synthesized in a single step.
• The developed hinges facilitated the preparation of bicyclic peptides with significantly improved solubility.
• Azide-modified TATB and TBMT derivatives enabled the creation of cyclized peptides for protein mimic applications.

Conclusions:

• The novel polar hinges TATB and TBMT are effective tools for peptide cyclization.
• These hinges lead to bicyclic and cyclized peptides with enhanced solubility and biological activity.
• The developed methodology provides a pathway for creating advanced peptide-based scaffolds and protein mimics.