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Updated: Jul 17, 2025

Modification and Functionalization of the Guanidine Group by Tailor-made Precursors
Published on: April 27, 2017
Site-Selective Modification of Secondary Amine Moieties on Native Peptides, Proteins, and Natural Products with
Feng Gao1, Mengyang Chang2, Xiang Meng1
1Department of Pharmacology and Toxicology, R. Ken Coit College of Pharmacy, University of Arizona, 1703 E Mabel Street, Tucson, Arizona 85721, United States.
Abstract:
Site-selective modification of biologically relevant secondary amines in peptides, proteins, and natural products has been challenging due to the similar reactivity between primary and secondary amines. Even for the secondary amines, their reactivities are significantly influenced by their structures and environment. Herein, we report a ynone Michael bioconjugation method for selective modification of secondary amines in unprotected peptides and proteins and complex natural products. We show that fine tuning the electronic effect of the ynones enables controlling the Michael acceptor reactivity for the selective reaction with the structurally different secondary amines in densely functionalized complex structures and complicated biological environment.
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