An integrated strategy for rapid discovery and identification of the potential effective fragments of polysaccharides from Saposhnikoviae Radix

Abstract

Ethnopharmacological relevance: Saposhnikoviae Radix (SR) is a traditional Chinese medicine, known as "Fangfeng". As one of the main active components, Saposhnikoviae Radix polysaccharides (SP) demonstrated a range of biological activities, especially immunity regulation activity.

Aims of the study: This study aimed at exploring whether polysaccharides have activity after degradation, then discovering the potential effective fragments of SP.

Materials and methods: Here we establish the chromatographic fingerprints method for 32 batches of 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatives of oligosaccharides by HPLC, meanwhile evaluating its immunomodulatory activity in vivo. Then, the potential effective fragments of SP were screened out based on the spectrum-effect relationship analysis between fingerprints and the pharmacological results. Besides, liquid chromatography ion trap-time of flight mass spectrometry (LC-IT-TOF MS) coupled with multiple data-mining techniques was used to identify the potential effective oligosaccharides.

Results: These findings showed that the hydrolysate of SP have significant immunomodulatory, and the immunity regulation activity varies under different hydrolysis conditions. The 4 potential effective peaks of the hydrolysate of SP were mined by spectrum-effect relationship. Finally, the chemical structure of 4 potential effective oligosaccharide fragments of SP was elucidated based on LC-IT-TOF MS. F10 was inferred tentatively to be Hex¹→⁶Hex¹→⁶Hex¹→⁶Hex¹→⁶Hex¹→⁶Gal; F18 was confirmed to be Rhamnose; F14 was inferred tentatively to be Hex¹→⁴Hex¹→ ⁴Hex¹→⁴Gal and F25 was tentatively inferred to be Ara¹→⁶Gal.

Conclusions: This study may provide a sound experimental foundation in the exploration of the active fragments from macromolecular components with relatively complex structures such as polysaccharides.

Keywords: Discovery; Effective fragments; Identification; Polysaccharides; Saposhnikoviae Radix.