Abstract: The crude polysaccharide from Leccinum crocipodium (Letellier.) Watliag, obtained by water extraction and alcohol precipitation, was purified by sequential decolorization and deproteinization. Its molecular mass of was determined by gel permeation chromatography (GPC). Its monosaccharide composition was determined by high performance liquid chromatography (HPLC). Its purity was identified by UV-visible spectroscopy. Its structure was analyzed by Fourier transform infrared (FTIR) spectroscopy. Furthermore, Its effects on short-chain fatty acid contents in the cecum contents and feces of mice were explored. The results showed that the polysaccharide was composed of mannose, glucuronic acid, galacturonic acid, glucose, galactose, xylose and fucose in a molar ratio of 4.34:0.35:0.08:13.39:3.35:0.75:1.80, and its weight-average molecular mass was 1.540 × 105 Da. The FTIR spectrum proved the polysaccharide to be a pyran-type polysaccharide containing α-(1→6) glycosidic bond and β-glycosidic bond. Animal experiments showed that the polysaccharide had a significant effect on the production of acetic acid, propionic acid, n-butyric acid, isobutyric acid, n-valeric acid and isovaleric acid in the cecum contents and feces of mice, which varied greatly depending on its dose. The most pronounced effect was observed at high doses.

Key words: Leccinum crocipodium (Letellier.) Watliag; polysaccharides; structure; short-chain fatty acids