Bimodal Glycosyl Donors as an Emerging Approach Towards a General Glycosylation Strategy.

Organic synthesis provides an accessible route to preparative scale biological glycans, although schemes to access these complex structures are often complicated by preparation of multiple monosaccharide building blocks. Bimodal glycosyl donors capable of forming both α- and β-anomers selectively, are an emerging tactic to reduce the required number of individual synthetic components in glycan construction. This review discusses examples of bimodal donors in the literature, and how they achieve their stereocontrol for both anomers.

Co-factor prosthesis facilitates biosynthesis of azido-pseudaminic acid probes for use as glycosyltransferase reporters.

Truncated thioester ,-diacetylcysteamine (SNAc) was utilised as a co-factor mimic for PseH, an acetyl-coA dependent aminoglycoside -acetyltransferase, in the biosynthesis of the bacterial sugar, pseudaminic acid. Additionally, an azido-SNAc analogue was used to smuggle 7-azide functionality into the pseudaminic acid backbone, facilitating its use as a reporter of pseudaminyltransferase activity.

Preparation and Application of an Inexpensive α-Formylglycine Building Block Compatible with Fmoc Solid-Phase Peptide Synthesis.

α-Formylglycine (fGly) is a rare residue located in the active site of sulfatases and serves as a precursor to pharmaceutically relevant motifs. The installation of fGly motifs into peptides is currently challenging due to degradation under the acidic and nucleophile-rich conditions accompanying resin cleavage during solid-phase peptide synthesis. We report the synthesis of acid- and nucleophile-tolerant α-formylglycine building blocks from vitamin C and use them to prepare callyaerin A, a macrocyclic peptide containing an fGly-derived motif.