Purification, characterization and hypoglycemic activity of extracellular polysaccharides from Lachnum calyculiforme

Polysaccharides produced by Lachnum have been found as biologically active substances in recent years. Herein, extracellular polysaccharides from Lachnum calyculiforme (LEP) fermenting liquor was obtained by the process of Sevag deproteination, H2O2 decolorization and salting out. LEP-1 was separated and sequentially purified from LEP through DEAE-Cellulose 52 and Sephadex G-100 column chromatography. The results showed that LEP-1 was detected as the homogeneous component with molecular weight of about 445.363 kDa by the high performance liquid gel permeation chromatography (HPGPC). Furthermore, we demonstrated that LEP-1 was glucose polymer by GC–MS analysis. IR and NMR spectroscopy (1H, 13C) analysis indicated that the glucose conformation was pyranose-type. Diabetic mice experiments showed that the LEP-1 had a strong hypoglycemic effect in alloxan diabetic mice with dose-dependent relationship.