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Cyclodextrins are widely used as carriers of small molecules for drug delivery owing to their remarkable host properties and excellent biocompatibility. However, cyclic oligosaccharides with different sizes and shapes are limited. Cycloglycosylation of ultra‐large bifunctional saccharide precursors is challenging due to the constrained conformational spaces. Herein we report a promoter‐controlled cycloglycosylation approach for the synthesis of cyclic α‐(1→6)‐linked mannosides up to a 32‐mer. Cycloglycosylation of the bifunctional thioglycosides and (Z)‐ynenoates was found to be highly dependent on the promoters. In particular, a sufficient amount of a gold(I) complex played a key role in the proper preorganization of the ultra‐large cyclic transition state, providing a cyclic 32‐mer polymannoside, which represents the largest synthetic cyclic polysaccharide to date. NMR experiments and a computational study revealed that the cyclic 2‐mer, 4‐mer, 8‐mer, 16‐mer, and 32‐mer mannosides adopted different conformational states and shapes. [ABSTRACT FROM AUTHOR]

Carbohydrates, Conformational Analysis, Cyclic Oligosaccharides, Cycloglycosylation, Glycosylation Keywords: Carbohydrates; Conformational Analysis; Cyclic Oligosaccharides; Cycloglycosylation; Glycosylation EN Carbohydrates Conformational Analysis Cyclic Oligosaccharides Cycloglycosylation Glycosylation 1 1 1 10/18/23 20231023 NES 231023 B Cyclic oligosaccharides b such as cyclodextrins are extensively employed as carriers fo drug delivery owing to their remarkable host properties and excellent biocompatibility. In their Research Article (e202307851), Peng Xu, Alba Silipo, You Yang et al. present a promoted-controlled cycloglycosylation approach for the synthesis of a series of cyclic mannosides up to a 32-mer. [Extracted from the article]

In their Research Article (e202307851), Peng Xu, Alba Silipo, You Yang et al. present a promoted-controlled cycloglycosylation approach for the synthesis of a series of cyclic mannosides up to a 32-mer. Keywords: Carbohydrates; Conformational Analysis; Cyclic Oligosaccharides; Cycloglycosylation; Glycosylation EN Carbohydrates Conformational Analysis Cyclic Oligosaccharides Cycloglycosylation Glycosylation 1 1 1 10/18/23 20231023 NES 231023 B Cyclic oligosaccharides b such as cyclodextrins are extensively employed as carriers fo drug delivery owing to their remarkable host properties and excellent biocompatibility. Carbohydrates, Conformational Analysis, Cyclic Oligosaccharides, Cycloglycosylation, Glycosylation. [Extracted from the article]

Flavobacterium strains exert a substantial influence on roots and leaves of plants. However, there is still limited understanding of how the specific interactions between Flavobacterium and their plant hosts are and how these bacteria thrive in this competitive environment. A crucial step in understanding Flavobacterium - plant interactions is to unravel the structure of bacterial envelope components and the molecular features that facilitate initial contact with the host environment. Here, we have revealed structure and properties of the exopolysaccharides (EPS) produced by Flavobacterium sp. Root935. Chemical analyses revealed a complex and interesting branched heptasaccharidic repeating unit, containing a variety of sugar moieties, including Rha, Fuc, GlcN, Fuc4N, Gal, Man and QuiN and an important and extended substitution pattern, including acetyl and lactyl groups. Additionally, conformational analysis using molecular dynamics simulation showed an extended hydrophobic interface and a distinctly elongated, left-handed helicoidal arrangement. Furthermore, properties of the saccharide chain, and likely the huge substitution pattern prevented interaction and recognition by host lectins and possessed a low immunogenic potential, highlighting a potential role of Flavobacterium sp. Root935 in plant-microbial crosstalk. [Display omitted] [ABSTRACT FROM AUTHOR]