RESUMO
In this study, an active component UP1-1 was isolated from Chinese Huangshan Umbilicaria esculenta via hot water extraction and purified by anion-exchange and gel-filtration chromatography. UP1-1 mainly composed of galactose, mannose and glucose in a molar ratio of 0.8:1.0:4.6 with an average molecular weight of 281 kDa. Methylation analysis of UP1-1 revealed the major glycosidic bonds comprised 1,6-linked Glcp, 1,4-linked Glcp, t-linked Glcp, 1,3,6-linked Manp, 1,3-linked Galp, t-linked Galp at the ratio of 2.28:0.38:0.32:0.63:0.25:0.29. Structural analysis results revealed that the backbone of UP1-1 consisted of â6)-ß-D-Glcp-(1â, â6)-ß-D-Manp-(1â, â4)-ß-D-Glcp-(1 â residues with side chains of â3)-ß-D-Galp-(1â, ß-D-Galp-(1 â and ß-D-Glcp-(1 â branches located at O-3 position of â6)-ß-D-Manp-(1â. Immunostimulatory activity tests showed that UP1-1 could promote the phagocytic activity and NO production of RAW 264.7 cells in a dose-dependent manner. UP1-1 could significantly improve the proliferation effect of RAW 264.7 cells at the concentration of 50 µg/mL. Thus, UP1-1 exerted good immunostimulatory activity, suggesting that UP1-1 has a great potential application in pharmacological industry.