Synthesis of novel peptide linkers: simultaneous cyclization and labeling.

Synthesis of novel peptide linkers was accomplished by monocarboxylation of 1,3,5-tris(bomomethyl)benzene with a wide variety of carboxylic acids in the presence of diisopropylethylamine. These reagents can be used to simultaneously cyclize and label peptides containing two cysteines. Many labels are compatible with this method including lipids, fluorescent groups, and biotin.