An extensive phytochemical analysis of the saponin content has been undertaken on leek, Allium porrum L., sown and collected at different seasons. As a result of this investigation, eight saponins (1-8) have been isolated, four of them (5-8) being novel compounds. Compounds 5 and 6, possessing the same tetrasaccharide moiety of compounds 1 and 3, display very unusual spirostane aglycones, 12-ketoporrigenin and 2,12-diketoporrigenin (named porrigenin C), respectively, recently isolated for the first time as free sapogenin in the same plant. Compounds 7 and 8 are rare cholestane bidesmosides possessing a di- and trisaccharide residues linked to a polyhydroxycholesterol aglycone, respectively. The structures of the isolated compounds have been determined by nondegradative spectroscopic analysis, mainly based on NMR. All the eight saponins isolated from leek were tested for their cytotoxic activity against two different cell lines in vitro, and compounds 1, 2, and 6 resulted particularly active.
NMR, cytotoxic activity, saponins, Liliaceae, Allium porrum L.
NCBI PubMed ID: 10956133Publication DOI: 10.1021/jf000331vJournal NLM ID: 0374755Publisher: American Chemical Society
Correspondence: fattoru@unina.it
Institutions: Dipartimento di Chimica delle Sostanze Naturali, Università di Napoli Federico II, Napoli, Italy, Dipartimento di Scienze e Tecnologie Agroalimentari, Ambientali e Microbiologiche, Università degli Studi del Molise, Campobasso, Italy, Dipartimento di Farmacologia Sperimentale, Università di Napoli Federico II, Napoli, Italy
Methods: 13C NMR, 1H NMR, NMR-2D, FAB-MS, HPLC, extraction, optical rotation measurement, acetylation, cytotoxicity assay, evaporation, MPLC, HR-FAB-MS, optical density measurement
Found