# A Rational Synthesis of a Branched Decaarabinofuranoside Related to the Fragments of Mycobacterial Polysaccharides

## TL;DR

Scientists developed a new method to synthesize a complex sugar molecule related to tuberculosis bacteria, which could help in creating better diagnostic tests.

## Contribution

The study introduces a simplified synthesis method for branched decaarabinofuranosides using a silylated disaccharide donor and a Janus aglycone.

## Key findings

- A silylated Ara-β-(1→2)-Ara disaccharide was effectively used as a glycosyl donor to simplify oligoarabinofuranoside synthesis.
- The use of a Janus aglycone reduced the number of reaction steps in glycoside synthesis.
- The synthesized arabinans may be used to create conjugates for tuberculosis screening assays.

## Abstract

A rational synthesis of the branched decaarabinofuranoside with 4-(2-azidoethoxy)phenyl aglycone (a Janus aglycone) related to the non-reducing terminal fragments of the arabinogalactan and lipoarabinomannan from Mycobacterium tuberculosis was proposed. Since the most challenging step is the formation of a 1,2-cis glycosidic linkage, we have significantly simplified access to a library of oligoarabinofuranosides derived from Mycobacterium tuberculosis polysaccharides using a silylated Ara-β-(1→2)-Ara disaccharide as the glycosyl donor. The application of a Janus aglycone also allowed us to reduce the number of reaction steps in glycoside synthesis. The obtained arabinans can be useful to further prepare conjugates as antigens for creating tuberculosis screening assays.