Biology Reference
In-Depth Information
to the abundant polysaccharide and polypeptide chains and the sub-
sequent phosphorylase-catalyzed enzymatic polymerization of Glc-
1-P (Fig. 5.1).
6.2
Chemoenzymatic Synthesis of Amylose-
Grated Chitin and Chitosan
Chitin, a (1
4)-linked 2-acetamido-2-deoxy-
β
- d -glucan,
and
- d -glucan, are the most
abundant polysaccharides found in nature [8]. These polysaccharides
are regarded to be biodegradable and noncytotoxic, and have some
interesting biological activities. However, wide application of these
polysaccharides is limited because of their specific properties caused
by the regular saccharide chain structures. Therefore, to develop
the novel functional heteropolysaccharides based on chitin and
chitosan, the preparation of the amylose-grafted polysaccharides
was investigated.
Amylose-grafted chitin and chitosan were synthesized by the
chemoenzymatic method as follows (Fig. 6.1) [9,10]. First, the Glc
chitosan, a (1
4)-linked 2-amino-2-deoxy-
β
7
OH
O
HO
HO
OH
OH
O
OH
O
+
OH
O
O
HO
HO
NH 2
O
OH
n
O
HO
Chitosan
OH
5
OH
Maltoheptaose
NaBH 3 CN
OH
OH
OH
OH
OH
O
(CH 3 CO) 2 O
O
O
O
O
O
O
O
O
O
NH
NH
NH 2
NH
HO
NH 2
HO
HO
HO
HO
O
n
n
OH
OH
HO
CH 3
HO
O
O
OH
OH
OH
OH
OH
OH
O
O
HO
HO
HO HO
OH
OH
O
O
OH
HO
OH
HO
O
O
5
5
OH
OH
Glc-1-P
Phosphorylase
Glc-1-P
Phosphorylase
OH
OH
OH
OH
OH
O
O
O
O
O
O
O
O
O
O
NH
NH
NH 2
NH
HO
NH 2
HO
HO
HO
HO
O
n
n
OH
OH
HO
CH 3
HO
O
O
OH
OH
OH
OH
OH
OH
O
O
HO
HO
HO HO
OH
OH
O
O
OH
HO
OH
HO
O
O
m
m
OH
OH
Figure 6.1
Chemoenzymatic synthesis of amylose-grafted chitin and
chitosan by means of phosphorylase-catalyzed enzymatic
polymerization.
Search WWH ::




Custom Search