Structure of an anti-tumor polysaccharide from Angelica sinensis (Oliv.) Diels

An arabinoglucan, named APS-1d with a molecular weight of 5.1 kDa determined by high-performance gel-permeation chromatography, was extracted from the roots of Angelica sinensis (Oliv.) Diels and further purified by DEAE-Sephadex A-25 and Sephadex G-100 columns. The monosaccharides in the APS-1d, determined by GC, consisted of Glc and Ara in molar ratio of 13.8:1. Using methylation analysis, partial acid hydrolysis, FT-IR, 1D and 2D NMR (H/H-COSY, HSQC, and HMBC) experiments, the structure of APS-1d was elucidated. APS-1d had a backbone composed of 1,4-α-d-glucopyranosyl residues, with branches attached to O-6 of some residues. The branches were composed of 1,6-α-d-Glcp residues, and terminated with β-l-arabinofuranose residues. The anti-tumor activities of APS-1d were investigated both in vitro and in vivo. MTT assay revealed that APS-1d significantly inhibited the proliferation of human cervix carcinoma HeLa cells and lung carcinoma A549 cells in vitro. Furthermore, APS-1d inhibited the growth of the tumors on the mice transplanted S180 in a dose dependent manner. The inhibitory rate in mice treated with 100 mg/kg APS-1d reached to 50.7%.