Configuration of the vitamin E analogue garcinoic acid extracted from Garcinia Kola seeds

Chirality. 2009 May;21(5):519-24. doi: 10.1002/chir.20630.

Abstract

Vitamin E derivatives bearing a carboxylic group have recently gained great attention because of their antitumoral properties. Garcinoic acid (trans-13'-carboxy-delta-tocotrienol) is a vitamin E analog extracted from Garcinia Kola seeds in which the carboxylic group is at the end of the aliphatic side chain and reported to be a racemate based on the optical rotation measurements. However, CD determination of a sample of the acid analyzed by us gave a positive peak at 208 nm, indicating that it is not a racemate. To assess the enantiomeric composition of garcinoic acid, it was thus transformed to alpha-tocopherol and analyzed by chiral HPLC on column OD-H. On the basis of the elution order of alpha-tocopherol stereoisomers, the garcinoic acid sample resulted to be enantiopure with R configuration at carbon 2 of the chroman ring. Moreover, in a preliminary test, the acid and some of its derivatives showed a marked antiproliferative effect on glioma C6 cancer cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anticarcinogenic Agents / pharmacology*
  • Antioxidants / chemistry
  • Antioxidants / pharmacology*
  • Apoptosis / drug effects
  • Benzopyrans / chemistry
  • Benzopyrans / pharmacology*
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Chromatography, High Pressure Liquid
  • Drug Screening Assays, Antitumor
  • Garcinia kola / chemistry*
  • Humans
  • Molecular Structure
  • Plant Extracts / pharmacology
  • Seeds / chemistry
  • Stereoisomerism
  • Tocopherols / chemistry*
  • Tocopherols / pharmacology
  • Vitamin E / analogs & derivatives
  • Vitamin E / chemistry
  • alpha-Tocopherol / chemistry
  • alpha-Tocopherol / pharmacology

Substances

  • Anticarcinogenic Agents
  • Antioxidants
  • Benzopyrans
  • Plant Extracts
  • garcinoic acid
  • Vitamin E
  • tocotrienol, delta
  • alpha-Tocopherol
  • Tocopherols