Homoisoflavonoids from the bulbs of Bellevalia longipes and an assessment of their potential cytotoxic activity

Seven undescribed homoisoflavonoids were identified from the bulbs of Bellevalia longipes Post (Asparagaceae) as well as thirteen known and one natural homoisoflavonoid that had been reported as a synthetic product previously. A general approach for recognizing homoisoflavonoids via NMR spectroscopy data were presented. The undescribed compounds were: 8-dehydroxy-5-O-demethyl-6-hydroxyscillapersicone, 6-methoxyscillapersicone, 5-O-demethyl-6-methoxyscillapersicone, 8-O-methylscillapersicone, 4′-O-methylscillapersicone, 4′,8-O,O-dimethylscillapersicone, 3′-O-methylscillapersicone, and 3-hydroxy-desmethylophiopogonanone A. Structures were determined based on analysis of HRMS and NMR data, while absolute configurations were assigned using ECD spectroscopy. Human cancer cell lines were used to assess the cytotoxic activities of the isolated compounds, where 3-dehydroxy-3′-hydroxyeucomol showed IC50 values of 0.62 μM, 5.36 μM, and 2.52 μM, when tested against MDA-MB-435 (melanoma), MDA-MB-231 (breast), and OVCAR3 (ovarian) cells, respectively.