Amide bonds are the most prevalent structures found in organic molecules and various biomolecules such as peptides, proteins, DNA, and RNA. The unique feature of amide bonds is their ability to form resonating structures, thus, they are highly stable and adopt particular three-dimensional structures, which, in turn, are responsible for their functions. The main focus of this review article is to report the methodologies for the activation of the unactivated amide bonds present in biomolecules, which includes the enzymatic approach, metal complexes, and non-metal based methods. This article also discusses some of the applications of amide bond activation approaches in the sequencing of proteins and the synthesis of peptide acids, esters, amides, and thioesters.
Lysine monomethylation (Kme) is an impactful post-translational modification (PTM) responsible for regulating biological processes and implicated in diseases,t hus there is great interest in identifying these methylation marks globally.However,the progress in this area has been challenging because the addition of as mall methyl group on lysine leads to negligible change in the bulk, charge,a nd hydrophobicity.H erein, we report an empowering chemical technology selective triazenation reaction, which we term "STaR", of secondary amines using arene diazonium salts to achieve highly selective,r apid, and robust tagging of Kme peptides from ac omplex mixture under biocompatible conditions. Although the resulting triazene-linkage with Kme is stable,we highlight the efficient decoupling of the triazene-conjugate to affordunmodified starting components under mild conditions when desired. Our work establishes au nique chemoselective, traceless bioconjugation strategy for the selective enrichment of Kme PTMs.
Here we solve a long-standing challenge of the siteselective modification of secondary amides and present a simple twostep, metal-free approach to selectively modify a particular secondary amide in molecules containing multiple primary and secondary amides. Density functional theory (DFT) provides insight into the activation of C−N bonds. This study encompasses distinct chemical advances for late-stage modification of peptides thus harnessing the amides for the incorporation of various functional groups into natural and synthetic molecules.
Rapid synthesis of the pentacyclic core structure of macroline-type indole alkaloids, and its application in the total synthesis of macroline and alstomicine is described. The core structure was accomplished in a highly stereocontrolled manner via two key steps, Ireland-Claisen rearrangement and Pictet-Spengler cyclization, commencing from a readily available starting material l-tryptophan, which obviated the need of a particular chiral source as an external catalyst, reagent, or internal auxiliary.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.