Synthesis and applications of alkylated C-sugars as peptide bioconjugates

Summary Permethylated C-sugars affect the stability and solubility of their carbohydrate precursors and may represent an important group of bioconjugates. When properly functionalized, these units can be appended to the N- and C-termini or to the side chains of peptides or other therapeutic candidates. In this report, we describe the synthesis of an amine-functionalized alkylated mannose derivative and confirm the configuration by determining the X-ray crystal structure of its nitrile precursor. An acid functionalized counterpart, when attached to the N-terminus of a NR box peptide analog, improved binding to estrogen receptor β (ERβ) but not to ERα.