Acta Chimica Sinica ›› 2013, Vol. 71 ›› Issue (05): 722-728.DOI: 10.6023/A13010109 Previous Articles     Next Articles

Article

桑白皮水提取多糖组分的分离纯化和结构特征

张晓曼, 廖文锋, 丛启飞, 董群, 丁侃   

  1. 中国科学院上海药物研究所 上海 201203
  • 收稿日期:2013-01-21 出版日期:2013-05-14 发布日期:2013-03-15
  • 通讯作者: 董群, qdong@mail.shcnc.ac.cn;丁侃,kding@mail.shcnc.ac.cn E-mail:kding@mail.shcnc.ac.cn
  • 基金资助:

    项目受国家自然科学基金(No. 30870551)及新药创制重大专项(No. 2012ZX09301001-003)资助.

Isolation and Structural Characterization of the Polysaccharides of Cortex Mori radices

Zhang Xiaoman, Liao Wenfeng, Cong Qifei, Dong Qun, Ding Kan   

  1. Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203
  • Received:2013-01-21 Online:2013-05-14 Published:2013-03-15
  • Supported by:

    Project supported by the National Natural Science Foundation of China (No. 30870551) and the Key New Drug Creation and Manufacturing Program (No. 2012ZX09301001-003).

Cortex mori radices, the dried root cortex of Morus alba L., is a clinically widely used traditional Chinese medicine, with the effects of anti-tussive, preventing asthma, hypoglycemic, antitumor, antibacterial and antioxidative. Up to now, its polysaccharides and their contribution to biological activities remain largely unknown. In this study, the root cortex was extracted with boiling water, followed by ethanol precipitation, fractionation and purification by anion-exchange chromatography on DEAE-cellulose column and gel permeation chromatography on Sephacryl S-300 column. Three polysaccharides, CMA-a-1, CMA-a-5 and CMA-b1-1, were isolated from boiling-water extract, and characterized to be homogeneous fractions by high performance gel permeation chromatography (HPGPC). Their structural features were elucidated by sugar analyses, methylation analyses, IR, and NMR spectroscopic methods. Both CMA-a-1 and CMA-a-5 are found to be starch fractions. CMA-a-1, with an average molecular weight (MW) of 224 kDa, is an amylopectin-like polysaccharide with an average chain length (CL) of 23, containing 1,4-linked α-D-glucopyranosyl backbone, with 1, 6-linked glucose in the side chains attached to O-6 of backbone residues. CMA-a-5, with a MW of 15.5 kDa, is mainly an amylose fraction with an average chain length of 30. CMA-b1-1 was isolated from 0.2 mol·L-1 NaCl-eluted fraction upon anion-exchange chromatography, and characterized as a RG-I type pectic polysaccharide, which contains a backbone composed of alternating 1,4-linked α-D-galacturonic acid and 1,2-linked α-L-rhamnose residues, with various branches attached to O-4 of rhamnose residues, comprising of T-, 1,3-, 1,5-, 1,3,5-linked Araf, T-,1,6-, 1,3,6-linked Galp, 1, 4-linked Xylp, and 1, 4-linked Glcp. MTT method showed that CMA-b1-1 could inhibit the proliferation of SMMC7721 liver cancer cells and showed no impairment to L02 normal liver cells. This study suggested that the boiling water extract of cortex mori radices contains mainly starch and pectic fraction as the major component polysaccharides, and that the RG-I polysaccharide in vitro can inhibit the liver cancer cell proliferation, but the starch fractions cannot.

Key words: cortex mori radices, Morus alba L., polysaccharide, chemical structure, antitumor