Characterization and functional elucidation of a fucosylated 1,6-α-d-mannogalactan polysaccharide from Antrodia cinnamomea

Antrodia cinnamomea is a valuable polyporaceous edible fungus native to Taiwan. It was reported to provide a number of pharmaceutical benefits. A. cinnamomea was cultured, the polysaccharides (PSs) were extracted and chromatographically fractionated, and their biological functions were evaluated. The PS subfractions (B85PS-I–V) showed differential inhibition of in vitro Matrigel tube formation (an indicator of angiogenesis inhibition) with IC50 values of 7.44, 16.41, 7.07, 7.98, and 16.33 μg/ml, respectively. Furthermore, A. cinnamomea PSs also blocked vascular endothelial growth factor (VEGF)-induced endothelial cell migration. B85PS-III and -V dose-dependently decreased angiogenic-related protein expressions, including inhibition of VEGF receptor (VEGFR) phosphorylation and angiopoietin-2 protein expression. To further purify and determine the structure of the bioactive PS, B85PS-III was chromatographically purified to give a water-soluble partial fucosylated 1,6-α-d-mannogalactan (B85PS-III-1) composed of a nonadecasaccharide repeating unit with a molecular mass of 4.17 × 102 kDa as shown below. The chemical structure of B85PS-III-1 was characterized by a monosaccharide analysis along with 1H, 13C, and 2D nuclear magnetic resonance spectroscopy.