Analysis of metabolites in simulated gastric fluid of Saposhnikoviae Radix polysaccharides

Abstract

To fully understand whether Saposhnikoviae Radix polysaccharides(SP) can be metabolized in gastric fluid and the meta-bolic behavior, this study systematically analyzed the metabolites in simulated gastric fluid of SP by high-performance liquid chromatography-ion trap time-of-flight mass spectrometry(HPLC-IT-TOF-MS) technology in combination with zebrafish immune activity evaluation. Based on the obtained accurate relative molecular mass, chromatographic retention behavior, MS fragmentation patterns, refe-rence standards, and relevant literature reports, 19 metabolites were analyzed and identified. Among them, five monosaccharides and 14 oligosaccharides were generated as metabolites. Several reducing sugars, including mannose, glucose, rhamnose, and xylose, were accurately identified in the gastric fluid metabolites. Zebrafish pharmacological evaluation results indicated that SP maintained good immune activity after gastric fluid metabolism, with the most significant increase in immune cell density observed at W3(simulated gastric fluid metabolism for 2 hours). Among the gastric fluid metabolites, M1 and M3(Hex-Hex-Man) may be most closely related to pharmacological activity and could be further studied as potential active fragments.