Rhamnogalacturonan II from the leaves of Panax ginseng C.A. Meyer as a macrophage Fc receptor expression-enhancing polysaccharide

Carbohydr Res. 1997 May 16;300(3):239-49. doi: 10.1016/s0008-6215(97)00055-4.


A complex pectic polysaccharide (GL-4IIb2) has been isolated from the leaves of Panax ginseng C.A. Meyer, and shown to be a macrophage Fc receptor expression-enhancing polysaccharide. The primary structure of GL-4IIb2 was elucidated by composition. 1H NMR, methylation, and oligosaccharide analyses. GL-4IIb2 consisted of 15 different monosaccharides which included rarely observed sugars, such as 2-O-methylfucose, 2-O-methylxylose, apiose, 3-C-carboxy-5-deoxy-L-xylose (aceric acid, AceA), 3-deoxy-D-manno-2-octulosonic acid (Kdo), and 3-deoxy-D-lyxo-2-heptulosaric acid (Dha). Methylation analysis indicated that GL-4IIb2 comprised 34 different glycosyl linkages, such as 3,4-linked Fuc, 3- and 2,3,4-linked Rha, and 2-linked GlcA, which are characteristic of rhamnogalacturonan II (RG-II). Sequential degradation using partial acid hydrolysis indicated that GL-4IIb2 contained alpha-Rhap-(1-->5)-Kdo and Araf-(1-->5) Dha structural elements, an AceA-containing oligosaccharide, and uronic acid-rich oligosaccharide chains in addition to an alpha-(1 -->4)-galacturono-oligosaccharide chain. FABMS and methylation analyses suggested that the AceA-containing oligosaccharide was a nonasaccharide in which terminal Rha was additionally attached to position 3 of 2-linked Arap of the octasaccharide chain observed in sycamore RG-II. Component sugar and methylation analyses assumed that the uronic acid-rich oligosaccharides possessed a similar structural feature as those in sycamore RG-II. GL-4IIb2 had a larger molecular mass (11,000) than sycamore RG-II (approximately 5000).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carbohydrate Sequence
  • Cells, Cultured
  • Macrophages / drug effects*
  • Macrophages / immunology
  • Molecular Sequence Data
  • Panax / metabolism*
  • Pectins* / chemistry
  • Pectins* / isolation & purification
  • Pectins* / pharmacology
  • Plants, Medicinal*
  • Receptors, Fc / biosynthesis*


  • Receptors, Fc
  • rhamnogalacturonan II
  • Pectins