Thursday, May 24, 2018

Organometallic Gold(III) Reagents for Cysteine Arylation

Marco S Messina, Julia M Stauber, Mary A Waddington, Arnold L. Rheingold, Heather D. Maynard, and Alexander M Spokoyny
J. Am. Chem. Soc., 2018

An efficient method for chemoselective cysteine arylation of unprotected peptides and proteins using Au(III) organometallic complexes is reported. The bioconjugation reactions proceed rapidly (<5 min) at ambient temperature in various buffers and within a wide pH range (0.5-14). This approach provides access to a diverse array of S-aryl bioconjugates including fluorescent dye, complex drug molecule, affinity label, poly(ethylene glycol) tags and a stapled peptide. A library of Au(III) arylation reagents can be prepared as air-stable, crystalline solids in one step from commercial reagents. The selective and efficient arylation procedures presented in this work broaden the synthetic scope of cysteine bioconjugation and serve as promising routes for the modification of complex biomolecules.

Covalent Plant Natural Product that Potentiates Antitumor Immunity

Misao Takemoto, Sara Delghandi, Masahiro Abo, Keiko Yurimoto, Minami Odagi, Vaibhav Pal Singh, Jun Wang, Reiko Nakagawa, Shin-ichi Sato, Yas...