Purification of polysaccharide from artificially cultivated <i>Anoectochilus roxburghii</i> (wall.) <b>Lindl</b>. by high‐speed counter current chromatography and its antitumor activity

Abstract

Abstract To establish a systematic method for the extraction, purification, characterization and antitumor activity study of polysaccharide from artificially cultivated Anoectochilus roxburghii (wall.) Lindl. (AC‐ARPS). High‐speed counter current chromatography with two‐phase aqueous systems was successfully applied to purify AC‐ARPS after one‐step separation. The purity of the AC‐ARPS obtained by phenol/sulfuric acid method was 95.01%. The chemical structures of AC‐ARPS were identified by a series of analytical methods including high‐performance liquid chromatography and liquid chromatography with mass spectrometry. High‐performance liquid chromatography and liquid chromatography with mass spectrometry indicated that AC‐ARPS was mainly composed of mannose, ribose, glucose, galactose and arabinose with a molar ratio of 1.00:8.47:47.30:1.17:1.19. AC‐ARPS is a homogeneous polysaccharide with a molecular weight of 25 681 Da. The antitumor effect of AC‐ARPS was evaluated on lung cancer A549, osteosarcoma 143B, rat adrenal pheochromocytoma PC 12, breast cancer MCF‐7, acute leukemia HL 60, chronic leukemia K562, colon cancer SW620, esophageal cancer OE 19, liver cancer HepG2, and neuroglioma U251 cells in vitro. AC‐ARPS showed the best inhibitory effect on OE 19 cells, and the IC 50 value was 5.67 ± 0.831 μmol/L. Fluorescence analysis and flow cytometry results showed that AC‐ARPS induced apoptosis and G2/M phase arrest in OE 19 cells.