Cholesteryl-modification of a glucomannan from bletilla striata and its hydrogel properties

Abstract

A glucomannan- Type polysaccharide, named BSP, was obtained from the tubers of Bletilla striata by ultrasonic- Assisted extraction, ethanol precipitation, deproteination and gel-permeation chromatography. HPLC analysis revealed that BSP contained mannose and glucose in the molar ratio of 3.5:1. Its molecular weight (Mw) was estimated to be 20 kDa. Methylation analysis, FT-IR and NMR analyses indicated that BSP consisted of (1→4)-linked β-D- glucopyranosyl residues and (1→4)-linked β-D-mannopyranosyl residues. Cholesteryl succinate was linked to BSP to make it more amphiphilic and the degree of substitution of cholesteryl succinate-BSP was 3.2%. The critical micelle concentration of modified BSP was 0.001 mg/mL, suggesting it could self- Assemble into nanoparticles in aqueous solution.