GFP-N, a novel heteropolysaccharide with a molecular weight of 1.26?×?107?Da, was isolated from maitake mushroom and purified by anion-exchange chromatography on a DEAE cellulose-52 column and gel-filtration chromatography on a Sephadex G-100 column. Its structure was characterized by Fourier transform infrared spectroscopy and one-dimensional (1H- and 13C-) NMR spectra, 1H1H correlation spectroscopy, and 1H13C heteronuclear single-quantum coherence spectroscopy. The structure of GFP-N consisted of L-arabinose, D-mannose and D-glucose and mainly contained three kinds of linkage type units as ?2,6)-a-D-Manp-(1???4, a-L-Araf-C1?, and ?3,6)-ß-D-Glcp-(1???. GFP-N could activate insulin receptor substrate 1, phosphatidylinositol-3-kinase, and glucose transporter 4 and inhibit c-Jun N-terminal kinase 1/2 for hypoglycemic effects in diabetic mouse livers. This is also the first report of the regulatory efficacy of Grifola frondosa polysaccharide on intestinal microflora in vivo using single-molecule real-time sequencing. These results indicated that polysaccharide from maitake mushroom could be as an enhancer to improve type 2 diabetes and a healthy food option to help regulate gut microbiota in diabetic individuals. Copyright © 2019 Elsevier Ltd. All rights reserved.
Journal: Food and chemical toxicology