Regioselective enzymatic glycosylation of natural polyhydroxylated compounds: galactosylation and glucosylation of protopanaxatriol ginsenosides

J Org Chem. 2001 Jan 12;66(1):262-9. doi: 10.1021/jo001424e.

Abstract

Ginsenoside Rg1 (1), the most representative Ginsenoside from Panax Ginseng C.A. Meyer belonging to the protopanaxatriol family, has been galactosylated by action of the beta-(1,4)-galactosyltransferase (GalT) from bovine colostrum, using UDP-galactose as an activated sugar donor. The enzyme showed the well-known specificity for the formation of a beta-linkage with the C-4 OH of the glucose acceptor, but it was not able to discriminate between the two glucose moieties of 1, giving a mixture of mono- and digalactosylated derivatives. Other natural Rg1-analogues such as F1, Rh1, Re, as well as the synthetic derivative 6'-O-acetyl-Rg1 have been also galactosylated, giving monolactosyl derivatives. GalT was also able to accept UDP-glucose as an activated sugar donor, giving rise to cellobiosyl derivatives of Rg1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbohydrate Sequence
  • Galactose / chemistry
  • Ginsenosides*
  • Glycosylation
  • Mass Spectrometry
  • Molecular Sequence Data
  • Panax / chemistry*
  • Plants, Medicinal*
  • Sapogenins / chemistry*
  • Saponins / chemistry
  • Triterpenes*

Substances

  • Ginsenosides
  • Sapogenins
  • Saponins
  • Triterpenes
  • protopanaxatriol
  • ginsenoside Rg1
  • Galactose