Secondary compounds in the Sardinian endemic Bituminaria morisiana, a multipurpose forage legume

The legume genus Bituminaria L. includes some species with an interest both for forage and pharmaceutical use. Nonetheless, their secondary compounds may influence the palatability of forage. Little information is available on the endemic Sardinian species Bituminaria morisiana (Pignatti & Metlesics) Greuter, and to our knowledge, its essential oils and furocoumarins have not been studied. We identified 59 constituents by GC/MS analysis of the essential oils of five B. morisiana populations (Punta Giglio, Siliqua, Bitti, Burcei, Monte Gonareddu). In particular, 'Siliqua' showed six low molecular weight hydrocarbons and Z-?-farnesene. This latter was the main constituent in all oil samples. Other main constituents were 9,12-octadecadien-1-ol-(Z, Z), and 9,12,15-octadecatrien-1-ol-(Z, Z, Z). The GC/MS analysis of methanol extracts showed a low content of psoralens in B. morisiana accessions, especially in 'Burcei'. An exception was 'Monte Gonareddu', characterized by a high content of psoralen. These outcomes revealed the existence of variability among populations for some secondary compounds that will allow plant selection for specific uses and forage production.