10 0 - EleA@UniSA - Università degli Studi di Salerno

Waterpepper has sometimes been used as a substitute for pepper in Europe
and as hot tasting spice in China and Japan. It has been used as a folk
medicine against tumors, uterine fibromas, and malignant ulcers.
On the other side it is known to be toxic to fishes, pigs and sheeps. Some
metabolites in the barks of Canellaceae and Warbugia are widely used in folk
medicine to alleviate toothache, rheumatisms, general pains, malaria, and also
widely used as spices in food.
Polygodial (1.1) has been also isolated from the marine mollusk Dendrodoris
limbata (Figure 1.5)
FIGURE 1.5- Dendrodoris limbata
Due to their defensive role these compounds must be easily available by the
producer organisms, however their toxicity requires a careful storage.
To this purpose at least two strategies are used: the first and most
straightforward is to store the dialdehydes in special cavities or cells. For
example unsaturated dialdehydes have been found in leaves cavities of the
plant Polygonum hydropiper. When an herbivore bites and chews the plant the
cavity walls are crushed and the pungent dialdehydeis distributed.
Other organisms have elaborated more sophisticated systems for the storage of
these metabolites, transforming them in a masked form. For instance, the
nudibranch species Dendrodoris limbata stores olepupuane (1.9), at the end of
the mantle. The precursor olepupuane is transformed to polygodial (1.1), by the
contact with predators. (Scheme 1.1)
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