The condensed tannins (syn. polymeric proanthocyanidins) represent a major group of phenolic compounds in woody and some herbaceous plants (1-3). Their exceptional concentrations in the barks and heartwoods of a variety of tree species have resulted in their commercial extraction with the initial objective of applying the extracts in leather manufacture (4). Essentially all of their biological significance, e. g. the protection of plants from insects, diseases and herbivores, and most of the current, e. g. leather manufacture, and also most promising new uses, e. g. pharmaceuticals or wood...