Journal of Chemical Ecology

, Volume 32, Issue 10, pp 2253–2267

Ellagitannins have Greater Oxidative Activities than Condensed Tannins and Galloyl Glucoses at High pH: Potential Impact on Caterpillars

Authors

    • Departments of Molecular, Cellular and Developmental Biology and Ecology and Evolutionary BiologyUniversity of Michigan
  • Christopher P. Jones
    • Departments of Molecular, Cellular and Developmental Biology and Ecology and Evolutionary BiologyUniversity of Michigan
  • Ann E. Hagerman
    • Department of Chemistry and BiochemistryMiami University
  • Maarit Karonen
    • Laboratory of Organic Chemistry and Chemical BiologyDepartment of Chemistry, University of Turku
  • Juha-Pekka Salminen
    • Laboratory of Organic Chemistry and Chemical BiologyDepartment of Chemistry, University of Turku
Article

DOI: 10.1007/s10886-006-9143-7

Cite this article as:
Barbehenn, R.V., Jones, C.P., Hagerman, A.E. et al. J Chem Ecol (2006) 32: 2253. doi:10.1007/s10886-006-9143-7

Abstract

Plants synthesize a diversity of tannin structures but little is known about whether these different types have different oxidative activities in herbivores. Oxidative activities of hydrolyzable and condensed tannins were compared at pH 10 with two methods: EPR spectrometry was used to quantify semiquinone radicals in anoxic conditions and a spectrophotometric assay was used to measure the rate of browning of phenolics oxidized in ambient oxygen conditions. A little-studied group of hydrolyzable tannins (ellagitannins) contained the most active tannins examined, forming high concentrations of semiquinone radicals and browning at the highest rates. On average, galloyl glucoses and high-molecular-weight gallotannins had intermediate to low oxidative activities. Condensed tannins generally formed low levels of semiquinone radicals and browned most slowly. The results suggest that ellagitannin-rich plants have active oxidative defenses against herbivores, such as caterpillars, whereas the opposite may hold true for plants that contain predominantly condensed tannins or high-molecular-weight gallotannins.

Key words

TanninEllagitanninCondensed tanninGalloyl glucoseGallotanninPhenolic compoundsOxidationSemiquinone radicalPlant–herbivore interactionsCaterpillar

Copyright information

© Springer Science+Business Media, Inc. 2006