How the polarity of carbohydrates can be used in chemistry - Carbohydrate Chemistry: Chemical and Biological Approaches - page 31

How the polarity of carbohydrates can be
used in chemistry
Rui Xu a,b and Yves Queneau* a,b,c
DOI: 10.1039/9781849739986-00031
Carbohydrates are the polar stars of sustainable chemistry. Their polarity induces physico-
chemical properties which can be used in different ways, either by bringing solubility
assistance to low water-soluble compounds or providing amphiphilic character to
hydrophobic molecules. This chapter covers some aspects of the use of carbohydrates in
sustainable chemistry, including notably Lubineau's glyco-organic compounds used in
hydrophobic-effect driven reactions in water, increased hydrophobic effects due to the
presence of carbohydrate solutes in water and various applications in the surfactant and
monomer fields.
1 Introduction
Because carbohydrates are ubiquitous in Nature, their chemistry is fas-
cinating and finds relevance with biology and medicine, agriculture, food
and nutrition, materials, fine chemicals, energy, etc. Being largely avail-
able, it is possible to use carbohydrates as a resource. In many, if not all,
fields and applications, one main, essential character of carbohydrates
on which many of their properties depend, is the presence of numerous
hydroxyl groups, in one word, their polarity. However this should not be
regarded as a simplistic characteristic, since the number and the
stereochemistry of hydroxyl groups are what differentiate sugars among
themselves. The apparently little structural differences in the hydroxy-
lation pattern of mono- or disaccharides, oligosaccharides or poly-
saccharides induce important and subtle consequences on their
biological role. The three-dimensional polarity mapping in oligo-
saccharides which decorate cells results in a biological language which
controls or interferes with many physiological and pathological events. It
is also the basis of the physical and materials properties for structural
polysaccharides in plants.
On the physico-chemical point of view, the key relevant property of
carbohydrates is their ability to establish hydrogen bonding which for
most of small size carbohydrates and some polysaccharides, results in
good or high water solubility (except when aggregation of polymer chains
through extremely solid intermolecular H-bonding networks in some
polysaccharides prevents the access of water molecules). The purpose of
a
b Institut de Chimie et de Biochimie Mol´culaires et Supramol´culaires, UMR 5246;
CNRS; Universit ´ de Lyon; Universit ´ Lyon 1; INSA-Lyon; CPE-Lyon; B ˆ t. Curien,
43 Bd du 11 Novembre 1918, F 69622 Villeurbanne, France
c Department of Chemistry, University of Hull, Cottingham Road, Hull HU6 7RX, UK