Chemoenzymatic syntheses of amylose-grafted chitin and chitosan.
Amylose-grafted chitin and chitosan were synthesized by chemoenzymatic methods according to the following reaction manners. First, maltoheptaose was introduced to chitosan by a reductive amination using sodium cyanotrihydroborate in a mixed solvent of 1.0 mol/L aqueous acetic acid and methanol at room temperature to produce a maltoheptaose-grafted chitosan (1). The functionality of maltoheptaose to chitosan in 1 depended on reaction time. The phosphorylase-catalyzed enzymatic polymerization of R-D-glucose 1-phosphate was then performed from 1 to obtain amylose-grafted chitosan (2). Maltoheptaose-grafted chitin (3) was synthesized by N-acetylation of 1 using acetic anhydride in a mixed solvent of aqueous acetic acid and methanol. Then, synthesis of amylose-grafted chitin (4) was performed by the phosphorylase-catalyzed enzymatic polymerization under conditions the same as those for 2. The average DPs of amylose graft chains in 2 and 4 depended on the feed ratios of R-D-glucose 1-phosphate to maltoheptaose primers in 1 and 3.
Kaneko
Yoshiro
Y
Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan.
Matsuda
Shun-ichi
S
Kadokawa
Jun-ichi
J
D000107:Acetylation; D000688:Amylose / Q000737:chemistry*; D002686:Chitin / Q000138:chemical synthesis*; D048271:Chitosan / Q000737:chemistry*; D005936:Glucans / Q000737:chemistry; D055772:Green Chemistry Technology / Q000379:methods*; D006005:Phosphorylases / Q000737:chemistry
D005936:Glucans; D002686:Chitin; C031146:maltoheptaose; D000688:Amylose; D048271:Chitosan; D006005:Phosphorylases