Curdlan is a bacterial sourced polysaccharide, consisting of a linear backbone of β-1 → 3-linked glucose (Glc) units. The high interest in pharmaceutical applications of curdlan and derivatives thereof is fueling the study of multi-step sequences for regioselective modifications of its structure. Here we have developed semi-synthetic sequences based on a regioselective protection-sulfation-deprotection approach, allowing the access to some, new, low molecular weight curdlan polysaccharide derivatives with unprecedented sulfation patterns. Three different semi-synthetic schemes were investigated, all relying upon the installation of a cyclic benzylidene protecting group on Glc O-4,6-diols, followed by either direct sulfation and deprotection, or some additional steps – including a hydrolytic or oxidative cleavage of the benzylidene rings – prior to sulfation and deprotection. The six obtained polysaccharides were subjected to a detailed structural characterization by 2D-NMR analysis, revealing that some of them showed the majority of Glc units along the polymeric backbone decorated by unprecedented sulfation motifs
Exploiting diol reactivity for the access to unprecedented low molecular weight curdlan sulfate polysaccharides / Vessella, Giulia; Esposito, Fabiana; Traboni, Serena; Di Meo, Celeste; Iadonisi, Alfonso; Schiraldi, Chiara; Bedini, Emiliano. - In: CARBOHYDRATE POLYMERS. - ISSN 0144-8617. - 269:(2021), p. 118324. [10.1016/j.carbpol.2021.118324]
Exploiting diol reactivity for the access to unprecedented low molecular weight curdlan sulfate polysaccharides
Vessella, Giulia;Traboni, Serena;Iadonisi, Alfonso;Bedini, Emiliano
2021
Abstract
Curdlan is a bacterial sourced polysaccharide, consisting of a linear backbone of β-1 → 3-linked glucose (Glc) units. The high interest in pharmaceutical applications of curdlan and derivatives thereof is fueling the study of multi-step sequences for regioselective modifications of its structure. Here we have developed semi-synthetic sequences based on a regioselective protection-sulfation-deprotection approach, allowing the access to some, new, low molecular weight curdlan polysaccharide derivatives with unprecedented sulfation patterns. Three different semi-synthetic schemes were investigated, all relying upon the installation of a cyclic benzylidene protecting group on Glc O-4,6-diols, followed by either direct sulfation and deprotection, or some additional steps – including a hydrolytic or oxidative cleavage of the benzylidene rings – prior to sulfation and deprotection. The six obtained polysaccharides were subjected to a detailed structural characterization by 2D-NMR analysis, revealing that some of them showed the majority of Glc units along the polymeric backbone decorated by unprecedented sulfation motifsI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.