Photochemical Transformations of Peptides Containing the -(2-Selenoethyl)glycine Moiety.

The diselenide bond has attracted considerable attention due to its ability to undergo the metathesis reaction in response to visible light. In our previous study, we demonstrated visible-light-induced diselenide metathesis of selenocysteine-containing linear peptides, allowing for the convenient generation of peptide libraries. Here, we investigated the transformation of linear and cyclic peptides containing the -(2-selenoethyl)glycine moiety.

Stapling of leu-enkephalin analogs with bifunctional reagents for prolonged analgesic activity.

The design and synthesis of leu-enkephalin analogs by replacing the glycine residues with -(2-thioethyl)glycines and opening the cyclisation potential is presented. The cyclization (stapling) was achieved using bifunctional reagents (hexafluorobenzene and trithiocyanuric acid derivatives). The CD conformational studies of the stapled analogs suggest that the peptides adopt the type I β-turn conformation, which is in agreement with the theoretical analysis.

Visible Light-Induced Templated Metathesis of Peptide-Nucleic Acid Conjugates with a Diselenide Bridge.

The use of template molecules as chemical scaffolds that significantly influence the course of the reaction has recently been intensively studied. Peptide nucleic acids (PNA) are molecules that mimic natural nucleic acids. They are a promising matrix in such reactions because they possess high affinity and specificity in their interactions.

Microwave-assisted solid-phase synthesis of lactosylated peptides for food analytical application.

The lactosylation of whey proteins affects their properties, especially their allergenicity and nutritional value, which matters in infant feeding. The quantification of lactosylated peptides requires analytically pure standards which are not commercially available. Herein, we proposed a fast, simple, and efficient protocol for the synthesis of lactosylated peptides on solid support based on microwave-assisted synthesis combined with boronate affinity chromatography utilizing the functionalized resin developed in our research group.

Alkyl Thiocyanurates as Thioester Mimetics. Transthioesterification and Ligation Reactions with High Potential in Dynamic Covalent Chemistry.

Alkyl thiocyanurates, the compounds formed in the SN reaction of thiocyanuric acid and alkyl halides, are susceptible to transthioesterification and ligation with molecules containing cysteamine, analogous to native chemical ligation of thioesters with peptides with an N-terminal cysteine moiety. The ligation is irreversible and results in the formation of mono- and disubstituted products dominantly. Transthioesterification, in contrast, is fully reversible and may be used in constructing dynamic systems.