Chitinase‐Catalyzed Synthesis of a Chitin‐Xylan Hybrid Polymer: A Novel Water‐Soluble β (1 → 4) Polysaccharide Having an N ‐Acetylglucosamine‐Xylose Repeating Unit

Summary: A chitin‐xylan hybrid polysaccharide having β (1 → 4)‐linked alternating structure of N ‐acetyl‐ D ‐glucosamine and D ‐xylose was synthesized via chitinase‐catalyzed polymerization. An oxazoline derivative of D ‐xylosyl‐ β (1 → 4)‐ N ‐acetyl‐ D ‐glucosamine ( 1 ) was effectively polymerized by the catalysis of chitinase from Bacillus sp., giving rise to a water‐soluble chitin‐xylan hybrid polysaccharide ( 2 ) in good yields. Molecular weights ( $\overline M _{\rm n}$ ) of 2 reached 1 500, which corresponds to 8–10 saccharide units.A chitin‐xylan hybrid polysaccharide ( 2 ) synthesized via chitinase‐catalyzed polymerization.