Targeted Chemical Modifications Identify Key Features of Carbohydrate Assemblies and Generate Tailored Carbohydrate Materials

Abstract

The molecular level description of carbohydrate assemblies is hampered by their structural complexity and the lack of suitable analytical methods. Here, we employed systematic chemical modifications to identify key noncovalent interactions that triggered the supramolecular assembly of a disaccharide model. While some modifications disrupted the supramolecular organization, others were tolerated, delivering important information on the aggregation process. The screening identified new geometries, including nanotubes, and twisted ribbons that were characterized with electron tomography and electron diffraction (ED) methods. This work demonstrates that the combination of synthetic chemistry and ED methods is a powerful tool to draw correlations between the molecular structure and the nanoscale architecture of carbohydrate assemblies.

The Flexibility of Oligosaccharides Unveiled Through Residual Dipolar Coupling Analysis

“…Saccharides also known as glycans, carbohydrates, or sugars are ubiquitous molecules in Nature, that serve in a large variety of roles, from plant cell construction and energy storage to mediation of key biomolecular recognition events ( Varki et al, 2017 ). Despite their chemical similarity, glycan functions largely vary depending on the monosaccharide composition (i.e., relative stereochemistry), as well as on the regio- and stereochemistry of the glycosidic linkages ( Gao and Chen, 2020 ; Gim et al, 2021 ). The chemical nature of the glycosidic linkages endows carbohydrates with a certain degree of flexibility that allows them to adopt a variety of three-dimensional shapes ( Woods, 2018 ; Gimeno et al, 2020 ), related to their structural or biological functions ( Kim et al, 2017 ; Gim et al, 2020 ; Srivastava et al, 2020 ; Dyukova et al, 2021 ).…”

Tuning the Chiral Structures from Self‐Assembled Carbohydrate Derivatives

“…Similarly, as shown in Figure 4d,e, supramolecular chirality can also be formed from oligosaccharide molecular chirality by chirality transfer. [ 39 ] l ‐glucose disaccharide (LL) and d‐glucose disaccharide (DD) can be utilized to form right‐handed and left‐handed fibers respectively, whereas the racemic mixture DD‐LL(s) can be assembled into flat lamellar structures by using three different DD:LL ratios (2:1, 1:1, and 1:2). [ 19 ] In addition, similar chirality has also been reported in some studies of hydrogels generated from oligosaccharide derivatives (Figure 4f–i).…”

“…d) Carbohydrate-aromatic interactions in modified oligosaccharides. Reproduced with permission [39]. Copyright 2021, MDPI.…”

Recent Advances in Electron Microscopy of Carbohydrate Nanoparticles

“…During the enzymatic reaction, when the DP of the synthesized molecules reaches the solubility limit, carbohydrates often spontaneously crystallize into NPs ( Hrmova et al, 2002 ; Hiraishi et al, 2009 ; Kobayashi et al, 2017 ; Grimaud et al, 2019 ) or larger spherulites ( Kobayashi et al, 2000 ; Faijes et al, 2004 ). There is a limited number of reports on the production of crystalline NPs based on the chemical synthesis of carbohydrates ( Gim et al, 2020 , 2021 ), even though the methodology has become well established in recent years ( Seeberger, 2015 ). While the chemical synthesis is generally labor-demanding and time-consuming, the resulting carbohydrates have well-defined molecular structures and monodisperse DPs and therefore are ideal starting materials for controlled crystallization and NP production.…”