Introduction - Engineering of Polysaccharide Materials - page 1

Chapter 1

Introduction

1.1 Important Features in Polysaccharides

Polysaccharides are one of the three major classes of
biomacromolecules in the plant, animal, and microbial kingdom,
which are vital materials for important functions, for example,

providing an energy source, acting as a structural material, and
conferring specific biological property [1,2]. They are structurally
consisting of monosaccharide residues linked through glycosidic
linkages. A glycosidic linkage is a type of covalent bond that joins
a monosaccharide residue to another group, which may or may
not be another saccharide residue. Polysaccharides have very
complicated structures owing to not only a structurally variety of
the monosaccharide residues but also the differences in stereo-
and regio-types of the glycosidic linkages (Fig. 1.1) [2]. In contrast,
the other two major biomacromolecules, i.e., nucleic acids and
proteins, have relatively simple structures because these substrates
are constructed by a type of specific linkage between several kinds
of nucleotides and 20 kinds of amino acids, respectively (Fig. 1.1)
[3]. A great variety of the polysaccharide structures contributes to
serve a whole range of their functions in the host organism, and a
subtle change in the structure of the monosaccharide unit or a type
of glycosidic linkage has a profound effect on the properties and
functions of the polysaccharides [4-6]. Therefore, synthesis of new

in vivo