Coumarins in Coronilla vaginalis in North East Italy

Abstract

The coumarin content was investigated in different plant parts of Coronilla vaginalis from North East Italy. Two hydroxycoumarins, scopoletin and daphnoretin, and the furocoumarin, psoralen, were found. The hydroxycoumarins are not present in all the different plant parts considered: the flowers have neither, and scopoletin in its free form is found only in the stems; in the other parts scopoletin is present mainly in the bound form. On the other hand, daphnoretin, mainly in the free form, was found in all the parts except stems and flowers. The furocoumarin, psoralen, is present in C. vaginalis ubiquitously in free and bound forms, although the psoralen concentration varies greatly in different plant parts; the greatest quantity occurring in the flowers. In ripe fruits, seeds appear to be an accumulation site for bound psoralen. It is postulated that the accumulation of scopoletin in the roots may play an allelopathic role. Bound psoralen accumulates mainly in seeds, where it may play an allelopathic role; it may have also a role in the prevention of seed decay by microorganisms.