The gut pathogen Clostridium bolteae has been associated with the onset of autism spectrum disorder (ASD). To create vaccines against C. bolteae,itisimportant to identify exact protective epitopes of the immunologically active capsular polysaccharide (CPS). Here,aseries of C. bolteae CPS glycans,u pt oa no ctadecasaccharide,w as prepared. Keyt o achieving the total syntheses is a[2+ +2] coupling strategy based on a b-d-Rhap-(1!3)-ad -Manp repeating unit that in turn was accessed by astereoselective b-d-rhamnosylation. The 4,6-O-benzylidene-induced conformational locking is ap owerful strategy for forming a b-d-mannose-type glycoside.Anindirect strategy based on C2 epimerization of b-d-quinovoside was efficiently achieved by Swern oxidation and borohydride reduction. Sequential glycosylation, and regioselective and global deprotection produced the disaccharide and tetrasaccharide,u pt ot he octadecasaccharide.G lycan microarray analysis of sera from rabbits immunized with inactivated C. bolteae bacteria revealed ahumoral immune response to the diand tetrasaccharide,b ut none of the longer sequences.T he tetrasaccharide may be ak ey motif for designing glycoconjugate vaccines against C. bolteae.

The development of glycoconjugate vaccines against Helicobacter pylori is challenging. An exact epitope of the H. pylori lipo‐polysaccharide (LPS) O‐antigens that contain Lewis determinant oligosaccharides and unique dd‐heptoglycans has not yet been identified. Reported here is the first total synthesis of H. pylori serotype O6 tridecasaccharide O‐antigen containing a terminal Ley tetrasaccharide, a unique α‐(1→3)‐, α‐(1→6)‐, and α‐(1→2)‐linked heptoglycan, and a β‐d‐galactose connector, by an [(2×1)+(3+8)] assembly sequence. Seven oligosaccharides covering different portions of the entire O‐antigen were prepared for immunological investigations with a particular focus on elucidation of the roles of the dd‐heptoglycan and Ley tetrasaccharide. Glycan microarray analysis of sera from rabbits immunized with isolated serotype O6 LPS revealed a humoral immune response to the α‐(1→3)‐linked heptoglycan, a key motif for designing glycoconjugate vaccines for H. pylori serotype O6.

Rubus chingii Hu has been used as a functional food for a long time. A novel pectin polysaccharide named RCHP-S from R. chingii Hu was structurally identified and explored its anti-inflammatory effect on colitis mice. RCHP-S was composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, and arabinose. NMR spectroscopy and methylation analysis showed that RCHP-S was mainly composed of HG-type pectin domains but also contains a small amount of RG-I. The anti-inflammatory tests indicated that the mouse macrophage RAW 264.7 cells pretreated with RCHP-S could show a significant inhibitory effect on the mRNA level of iNOS, IL-1β, IL-6, and TNF-α in vitro. Polysaccharide RCHP-S reduced the enteritis symptoms in dextran sulfate sodium (DSS)-induced colitis mice by inhibiting released inflammatory factors. These results indicated that the R. chingii Hu polysaccharide can be used as food additives for the treatment of intestinal inflammation.