支链聚乙烯亚胺辅助硼酸功能化磁性纳米粒子的制备及其用于人参皂苷的特异性富集
摘要
<p id=C2>Panax ginseng has a 5000-year-long history as a traditional herbal medicine in Eastern Asia and North America. It is also known as crown jewel in traditional Chinese herbs because of its wide pharmacological properties. Ginsenosides, a class of saponins containing triterpene aglycones and various sugar moieties, are the main active components of ginseng. Considering the low abundance of ginsenosides and other abundant interferences, separation of ginsenosides is essential prior to further analysis. Recently, our group demonstrated the potential of a boronate affinity material for the selective enrichment of ginsenosides. However, conventional boronate affinity materials suffer from an apparent drawback. The binding strength of boronic acids toward <italic>cis</italic>-diol-containing compounds is low, with dissociation constants (<italic>K</italic><sub>d</sub>) ranging from 10<sup>-1</sup> to 10<sup>-3</sup>mol/L. Thus, it is necessary to develop boronate affinity materials with high binding strength. In this study, we developed polyethyleneimine (PEI)-functionalized boronate affinity magnetic nanoparticles (BA-MNPs) for the selective enrichment of ginsenosides. Branched PEI was applied as a scaffold to amplify the number of boronic acid moieties, while 3-formylphenylboronic acid, which shows high affinity toward <italic>cis</italic>-diol-containing molecules, was used as the affinity ligand. In addition, the presence of the multi-glycan structure of ginsenoside leads to higher binding affinity between the PEI-BA-MNPs due to the synergistic multivalent binding effect. Combining with high performance liquid chromatography, a method for the selective analysis of ginsenosides was established. With ginsenoside Re as the representative and under the optimized conditions for magnetic solid-phase extraction, the developed method showed good linearity in the range of 50-800 μg/L, with a linear correlation coefficient (<italic>R</italic><sup>2</sup>) of 0.9681. At d