کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1373665 | 1500606 | 2016 | 11 صفحه PDF | دانلود رایگان |
• Efficient carboxymethylation of paramylon, Euglena-derived β-1,3-glucan, using heterogeneous reactions was established.
• Carboxymethylation using a heterogeneous system requires paramylon to be in an amorphous state.
• Carboxymethyl paramylons with a high DScm form nanofibers in the aqueous phase.
• Carboxymethyl paramylons with a low DScm form nanofibers in both the solid and aqueous phases.
Carboxymethylation of paramylon, a storage polysaccharide of Euglena, was explored using homogeneous and heterogeneous reaction systems. Homogeneous reactions yielded carboxymethyl paramylons with a low degree of substitution of carboxymethyl group (DScm) of ∼0.13. Heterogeneous reactions of paramylon with chloroacetic acid in a mixture of 2-propanol and a NaOH aqueous solution yielded carboxymethyl paramylons with a high DScm of up to ∼0.80. An essential step for successful carboxymethylation using the heterogeneous reaction systems devised in this study was the pretreatment of a paramylon particle to break its inherent highly crystalline state into an amorphous one. A high degree of substitution provided carboxymethyl paramylons with a nanofiber-forming ability in the aqueous phase while a low degree provided them with a fiber-forming ability in both the aqueous and solid phases.
Journal: Carbohydrate Polymers - Volume 152, 5 November 2016, Pages 468–478