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Identification of hydrolysable tannins in the reaction zone of Eucalyptus nitens wood by high performance liquid chromatography–electrospray ionisation mass spectrometry
Author(s) -
Barry K. M.,
Davies N. W.,
Mohammed C. L.
Publication year - 2001
Publication title -
phytochemical analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 72
eISSN - 1099-1565
pISSN - 0958-0344
DOI - 10.1002/pca.548
Subject(s) - chemistry , ellagic acid , gallic acid , chromatography , polyphenol , phenols , hydrolyzable tannin , catechin , proanthocyanidin , electrospray , eucalyptus nitens , high performance liquid chromatography , eucalyptus , organic chemistry , botany , antioxidant , biology
Abstract The first detailed analysis of the phenolic constituents of the reaction zones (tissue of antimicrobial defence) from the sapwood of a Eucalyptus spp. is presented. Plantation‐grown Eucalyptus nitens trees with stem decay resulting from pruning wounds were sampled and extracts were prepared from healthy sapwood and from reaction zone tissue. Analysis by HPLC with ESI‐MS revealed that a diverse range of hydrolysable tannins are present in both healthy sapwood and in reaction zone extracts, including over 30 gallotannins, ellagitannins and phenols. Eight tannins were unequivocally identified, including the gallotannins tri‐ O ‐galloyl‐β‐ D ‐glucose, tetra‐ O ‐galloyl‐β‐ D ‐glucose and penta‐ O ‐galloyl‐β‐ D ‐glucose, and the ellagitannins pedunculagin, tellimagrandin I, casuarinin, casuarictin and tellimagrandin II. The phenols gallic acid, ellagic acid and catechin were also identified. The ellagitannins (particularly pedunculagin) are considerably more abundant in the reaction zone than in the healthy sapwood and may contribute to the effectiveness of the reaction zone as an antimicrobial barrier. Copyright © 2001 John Wiley & Sons, Ltd.