Facile synthesis of trisaccharide moiety corresponding to antitumor activity in triterpenoid saponins isolated from Pullsatilla roots

Chem Pharm Bull (Tokyo). 2007 Dec;55(12):1734-9. doi: 10.1248/cpb.55.1734.

Abstract

A trisaccharide found in triterpenoid saponins isolated from Pullsatilla roots appears as an important promoiety for the enhancement of anticancer activity of their aglycones. Thus a facile synthetic method for a trisaccharide moiety, allyl-2,3,4-tri-O-benzoyl-alpha-L-rhamnopyranosyl-(1-->2)-[2,3,4,6-tetra-O-benzoyl-beta-D-glucopyranosyl-(1-->4)]-3-O-benzoyl-beta-L-arabinopyranoside (3), has been firstly developed through the regio- and stereoselective glycosylations from arabinose in total 16% yield via route 2 (eight steps). In this synthetic procedure, the protection of anomeric -OH of L-arabinose with equatorially oriented allyl group unlike with the axial 4-methoxybenzyl protecting group well promoted glycosyl bond formation between alpha-L-rhamnopyranosyl trichloroacetimidate and 2-OH of arabinose. As expected, the synthesized trisaccharide moiety 3 has no cytotoxicity (ED50: >100 microM) against three human cancer cell lines (A-549, SK-OV-3, and SK-MEL-2), respectively.

MeSH terms

  • Antineoplastic Agents, Phytogenic / chemical synthesis*
  • Antineoplastic Agents, Phytogenic / pharmacology*
  • Carbohydrate Sequence
  • Cell Line, Tumor
  • Drug Screening Assays, Antitumor
  • Humans
  • Indicators and Reagents
  • Molecular Sequence Data
  • Plant Roots / chemistry
  • Ranunculaceae / chemistry*
  • Saponins / chemical synthesis*
  • Saponins / pharmacology*
  • Trisaccharides / chemical synthesis*
  • Trisaccharides / pharmacology*
  • Triterpenes / chemical synthesis*
  • Triterpenes / pharmacology*

Substances

  • Antineoplastic Agents, Phytogenic
  • Indicators and Reagents
  • Saponins
  • Trisaccharides
  • Triterpenes