Automated Glycan Assembly of Mycobacterial Hexaarabinofuranoside and Docosasaccharide Arabinan (Ara<i>f</i>₂₃) Motifs found on <i>Mycobacterium tuberculosis</i>

Abstract Mycobacteria are covered in a thick layer of different polysaccharides that helps to avert the innate immune response. Lipoarabinomannan (LAM) and arabinogalactan (AG) are ubiquitously contained in these envelopes, and rapid access to defined oligo‐ and polysaccharides is essential to elucidate their structural and biological roles. Arabinofuranose (Ara f) residues in LAM and AG are connected either via α ‐1,2‐ trans linkages that are synthetically straightforward to install or the more challenging β ‐(1,2‐c is ) linkages. Herein, it was demonstrated that automated glycan assembly (AGA) can be used to quickly prepare 1,2‐ cis ‐ β ‐Ara f as illustrated by the assembly of a highly branched arabinan hexasaccharide and a docosasaccharide arabinan (Ara f 23 ) motif.