Synthesis And Characteristics Of Fatty Acid β-glucan Ester

Polymer micelles showstrong potential in solubilizing lipophilic substances, targeting transportation, protection and other aspects, and have become a multi-purpose platform involving pharmaceutical, nutrition, food processing. Among the study of polymeric micelles, due to have good biocompatibility and degradability, micelles based on hydrophobic polysaccharide have received much attention. However, up to now, report about the synthesis, characterization, and potential application of micells based on hydrophobic polysaccharide is few. In this study, we chosed oat β-glucan as the research subject, and studied the factors which influence the synthesis of fatty acif oat β-lucan ester (FAOGE), and on this base, the structure-self aggregation behavior and curcumin loading capacity (CLC) relationship were investigated, in order to develop a new kind of polymeric micelles derived from food. The research results are as follows:1. The effects of chain length of fatty acid (A), Mw of βglucan (B) and addition of acyl imidazole (C) on the degree of substitution (DS) of FAOGE follwed the follwing equation: DS=0.061+0.0028A-0.013B+0.014C-0.02A2-0.013B2-0.01C2-0.00025AB-0.00075AC-0. 0043BC Specific to see, the DS of FAOGE decreased with the Mw of βglucan and increased with the addition of acyl imidazole. However the chain length of fatty acid had little effect on DS.FAOGE with required DS could be synthesised by modulating the addition of acyl imidazole in the reaction system when specific oat β-glucan (with known Mw) and fatty acid (with known chain length) were used as substrates.2.The fluorescence spectrometry was used to find that beyond the critical aggregation concentration(CAC), FAOGE could self-aggregate in aqueous solution. Observed from the transmission electron microscopy and dynamic light scattering diagram, the prepared FAOGEs could be form spherical particles in aqueous solution, and the average size of the nanoparticles was in the range of 100-600 nm.The result of structure-self aggregation behavior of FAOGE revealed that the CAC value was decreased with the DS, acyl chain length and the decreased Mw of oat β-glucan, and the effect of interaction of DS and acyl chain length on the CAC of FAOGE is significant.3. Obtained from the result of structure-CLC relationship analyzed by response surface methodology (RSM) that, The relationship between the independent variables of Mw of βglucan (X1), DS of FAOGE (X2), and acyl chain length(X3) and CLC (Y1) followed the following equation:Y1=1.93+0.47X1+0.39X2+0.74X3+0.14X1X2+ 0.31X1X3+0.19X2X3+0.019X12-0.74X22+0.39X32. The equation shows that, whenMw of β-glucan is 16.8×104 g/mol,DS of FAOGE is 0.022 and acyl chain length is 10, the CLC reaches at the maximum value (4.05 wg/mg). The study also showed that the size of micelles of curcumin loaded FAOGE increased with the Mw of oat β-glucan, decreased with the acyl chain length and first increased and then decreased with the DS. According to FT-IR analysis results, we speculated that there was significant interactions occurred between the curcumin and FAOGE micelles.