Structure elucidation of arabinogalactoglucan isolated from Sedum sarmentosum Bunge and its inhibition on hepatocellular carcinoma cells in vitro.

Sedum sarmentosum Bunge (SS) is clinically used as Chinese medicine for hepatitis related diseases treatment. The purpose of this study was to explore the chemical structures of polysaccharides from this plant. A neutral polysaccharide (SSWP) was isolated and purified by ion-exchange chromatography and Superdex-75 column. The obtained SSWP was a homogenous one with a molecular weight of 21.5 kDa according to the high-performance gel permeation chromatography. The major monosaccharide composition of SSWP was arabinose, glucose and galactose in a molar ratio of 2.4:1:1.8. The methylation analysis showed that SSWP consists mainly of Ara f -(1→, →5)-Ara f -(1→, →3,5)-Ara f -(1→, →4)-Gal p -(1→, →4)-Glc p -(1→. The NMR result and enzymatic digestion data comprehensively indicated that SSWP was a novel arabinogalactoglucan-type structure. The anticancer assay in vitro exhibited that SSWP could effectively inhibit 48.9% of Huh-7 cells growth at 50 μg/mL and arrest cells at S-phase, and induce tumor cells apoptosis. Together, polysaccharide from S. sarmentosum Bunge could be a potential natural antitumor agent. [Display omitted] • Neutral polysaccharide (SSWP) was isolated from Sedum sarmentosum Bunge. • Monosaccharide composition and NMR results show SSWP was an arabinogalactoglucan. • SSWP was composed of T-Ara f , 1,3,5-Ara f , 1-5-Ara f , 1,4-Gal p and 1,4-Glc p. • The purified polysaccharide showed anti-hepatoma activities in vitro. • SSWP could arrest cell cycle at S-phase and induce apoptosis of Huh-7 cells. [ABSTRACT FROM AUTHOR]