ETHER-LINKED FERULIC ACID-AMIDES IN NATURAL AND WOUND PERIDERMS OF POTATO-TUBER

The occurrence of ether-linked ferulic acid amides (feruloyltyramine a nd/or feruloyloctopamine) in suberin-enriched samples of natural and w ound periderms of potato tubers was established by thioacidolysis and desulphuration, followed by GC-mass spectrometry of diagnostic dihydro feruloyltyramine. Analysis of samples premethylated in the presence of diazomethane showed that the major part of the ether bonds involved t he ferulic moiety of the amides; 20% of the amides released upon thioa cidolysis were nevertheless attached to cell walls through the tyramin e phenolic group. In addition, dicovalently linked ferulic acid amides were evidenced. These bridges were twice as abundant in the wound tha n in the natural periderm. Copyright (C) 1996 Published by Elsevier Sc ience Ltd