LOCALIZATION OF THE ELLAGITANNINS IN THE TISSUES OF QUERCUS-ROBUR AND QUERCUS-PETRAEA WOODS

The heartwoods of a pedunculate oak and a sessile oak were each dissected into four fractions according to tissue type. The ellagitannins roburins A-E, grandinin, castalagin, and vescalagin in each fraction were determined by HPLC. The ellagitannin distributions in the wood of the two species were found to be identical. Both the longitudinal parenchyma enclosing the earlywood and latewood vessels, and the ray parenchyma display high ellagitannin contents, with the ray parenchyma being particularly rich. The fibrous zone displayed the lowest ellagitannin concentration. It comprised the most abundant tissue mass, however, with its diffuse apotracheal and ray parenchyma of the uniseriate rays accounting for half of the total ellagitannins.