Tetrahydro-beta-carboline alkaloids occur in fruits and fruit juices. Activity as antioxidants and radical scavengers

J Agric Food Chem. 2003 Nov 19;51(24):7156-61. doi: 10.1021/jf030324h.


Tetrahydro-beta-carbolines are biologically active alkaloids that occur and accumulate in mammalian tissues, fluids, and brain, but their ultimate origin or biological role is still uncertain. Four tetrahydro-beta-carboline alkaloids: 1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid, 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid, 1-methyl-1,2,3,4-tetrahydro-beta-carboline, and 6-hydroxy-1-methyl-1,2,3,4-tetrahydro-beta-carboline, are found as naturally occurring substances in some fruit and fruit juices. These compounds occur in the microg/g level in those products, and a characteristic and distinct profile appears to exist depending on the type of fruit and juice involved. Thus, 1-methyl-1,2,3,4-tetrahydro-beta-carboline may appear in tomato, tomato juice, and kiwi; 6-hydroxy-1-methyl-1,2,3,4-tetrahydro-beta-carboline in bananas, pineapple, tomato, and their corresponding juices; and 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid in oranges and grapefruits, although it also occurred in most juices. Fruit-occurring tetrahydro-beta-carboline alkaloids acted as antioxidants and free radical scavengers in the ABTS assay when compared with ascorbic acid and Trolox. This suggests that tetrahydro-beta-carboline alkaloids might act as antioxidants when absorbed and accumulated in the body, contributing to the antioxidant effect of fruit products containing these compounds.

MeSH terms

  • Actinidia / chemistry
  • Alkaloids / analysis*
  • Alkaloids / chemistry
  • Ananas / chemistry
  • Antioxidants / analysis*
  • Antioxidants / chemistry
  • Benzothiazoles
  • Beverages / analysis*
  • Carbolines / analysis*
  • Carbolines / chemistry
  • Chromatography, High Pressure Liquid
  • Citrus / chemistry
  • Free Radical Scavengers / analysis*
  • Free Radical Scavengers / chemistry
  • Fruit / chemistry*
  • Mass Spectrometry
  • Musa / chemistry
  • Solanum lycopersicum / chemistry
  • Spectrometry, Fluorescence
  • Sulfonic Acids / chemistry


  • Alkaloids
  • Antioxidants
  • Benzothiazoles
  • Carbolines
  • Free Radical Scavengers
  • Sulfonic Acids
  • 2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid
  • tryptoline