Qualitative and quantitative analyses of secondary metabolites in aerial and subaerial of Scorzonera hispanica L. (black salsify)

Scorzonera hispanica commonly known as black salsify is a perennial herbaceous plant belonging to the Asteraceae family. The subaerial parts of black salsify are cultivated in Central and Southern Europe as a vegetable. There are only few reports on the chemical composition of S. hispanica. The aim of the present study was to determine the chemical composition of subaerial and aerial parts of this species. In total, twelve compounds were isolated and identified with spectroscopic methods, including a series of seven rare sesquiterpenoids – five bisabolane and two curcumenal derivatives. Furthermore, a fully validated HPLC–DAD–CAD method for the quantification of phenolic compounds of S. hispanica was developed. The cytotoxicities of lignan [(−)-syringaresinol (1)] and bisabolane derivatives from S. hispanica against several cancer cell lines were studied. (−)-Syringaresinol was the only compound active against myeloma cell lines and was also active against colon cancer cell lines. However, this lignan was also found to be cytotoxic for normal peripheral blood mononuclear cells (PBMCs). Two bisabolane derivatives were active against colon cancer cell lines and may be interesting as lead structures for the development of new anti-colon cancer agents.