Abstract: The aim of this study was the isolation, purification, monosaccharide composition and anticancer activity of polysaccharide fractions from Hongyang kiwi fruits. Crude polysaccharides were obtained through water extraction. Column chromatography was applied to isolate and purify polysaccharide fractions. High performance gel permeation chromatography (HPGPC) was carried out to test the purity and molecular masses of the fractions. Monosaccharide composition of the purest polysaccharide fraction was tested by high performance liquid chromatography (HPLC), and its characteristic functional groups were identified by Fourier transform infrared (FT-IR) spectroscopy. The in vitro growth inhibitory effect of the pure polysaccharide fraction on lung cancer cell NCI-H460, breast cancer cell MCF-7, liver cancer cell HepG2, gastric cancer cell SGC7901, and colorectal cancer cell HT29 were determined by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Four fractions (ACP-1, ACP-2, ACP-3 and ACP-4) were isolated from the crude polysaccharides. ACP-3 was the purest fraction with a molecular mass of 2 663 kD. The monosaccharide composition analysis indicated that ACP-3 consisted of L-rhamnose (17.78%), D-galacturonic acid (25.25%), D-galactose (25.45%), L-arabinose (20.51%), D-glucose (6.14%), D-mannose (2.13%), D-xylose (1.03%), D-glucuronic acid (0.97%) and D-fucose (0.74%). The characteristic absorbance of functional groups was observed in the FT-IR spectrum of ACP-3 fraction. The half maximal inhibitory concentrations (IC50) of ACP-3 against NCI-H460, MCF-7, HepG2, SGC7901 and HT29 cell lines were 0.646, 0.310, 0.642, 0.281 and 0.575 μmol/L, respectively. ACP-3 showed a significant inhibitory effect on the proliferation of all tested cancer cell lines.

Key words: Hongyang kiwi fruit, polysaccharide fraction, extraction and isolation, monosaccharide composition, anticancer activity