Chemische synthese verzweigter polysaccharide, 5. Kopplung von oligosacchariden und amylose an verschiedene träger durch hydrazonbindung

Abstract

Abstract The coupling of glucose and maltooligomers by hydrazone linkage to carriers by means of acid hydrazide groups was investigated. The following carriers were used: (1) linear polymers such as (a) poly(ethylene glycol) with carboxymethyl (CM) end groups, (b) CM‐amylose and CM‐cellulose, 6‐COOH amylose and 6‐COOH cellulose, pectic acid, alginic acid, poly(acrylic acid); (2) multifunctional centers such as (c) CM‐cyclodextrin, 1,3,5‐benzenetricarboxylic acid, 1,3,4,5‐benzenetetracarboxylic acid, crosslinked poly(acrylamide) (BIO‐GEL). The hydrazone linkage which is formed preferably in borate buffer at pH 8,5 was stable above pH 6 and could be split by mild acid treatment at pH 4. Maltooligomeric grafts of degree of polymerization DP ≧ 4 may be extended enzymatically by phosphorolytic synthesis to amylose chains of variable length. Primer activity of the bound maltooligomers for phosphorylase was obviously not hindered by the hydrazone linkage, by free hydrazide groups, or by synthetic polymers as carriers. ABA‐Block copolymers may be derived from(a), comb‐like molecules from (b), and different kinds of star‐like molecules from (c).