Structure and application of Ganoderma polysaccharide peptide GL-PPSQ2 / 中草药

ABSTRACT

Objective To study the structure of active polysaccharide peptide purified from Ganoderma lucidum aqueous extract, and used as a reference substance for the determination of polysaccharide peptide content in G. lucidum products. Methods GL-PPSQ2 was obtained by hot water extraction, separation and purification with membrane ultrafiltration and gel-filtration chromatography. The physicochemical determination and spectral date were used for structural identification. The content of polysaccharide peptide was detected by HPLC with UV detector, water was used as mobile phase and the flow rate was 1 mL/min. Results GL-PPSQ2 was a pure polysaccharide peptide with purity above 97%, molecular weight of 5.0 × 104, polysaccharide content of 87.17%, and yield of 0.49%. The monosaccharides composition analysis showed that GL-PPSQ2 was glucose-based polysaccharide with a small amount of mannose, which contained 16 kinds of amino acids with the total amount of amino acids of 5.04%. Based on the methylation analysis, 1D and 2D NMR spectroscopy, the repeating unit of GL-PPSQ2 was composed of →3)-β-D-Glcp-(1→backbone, with four repeating units connected a long chain branch at O-6 which was composed of α-D-Glcp-(1→, →4,6)-β-D-Glcp-(1→, →4)- β-D-Glcp-(1→ and →6)-β-D-Glcp-(1→ in sequence. Conclusion The active polysaccharide peptide was isolated and purified by membrane technology and gel chromatography. The method was simple and rapid, which provided a scientific basis for the quality control of polysaccharide peptide in G. lucidum extract and its products.