Chemical constituents from Morus notabilis and their cytotoxic effect

One new flavonoids named as notabilisin K (1), together with four known compounds, morusin (2), mulberrofuran A (3), neocyclomorusin (4) and mornigrol F (5) are separated from 95% ethanol extracts of the twigs of Morus notabilis. Compounds 2-5 are separated from this plant for the first time. Notabilisin I, notabilisin J exhibits certain effect against cells of HCT-116, HepG2 and A2780 with IC₅₀ values ranging from 1.47 μmol·L^-1 to 5.46 μmol·L^-1. Morusin exhibits strong effect against five kinds of human cancer cells (BGC823, A2780, HCT-116, HepG2 and NCI-H1650) with IC₅₀ values ranging from 0.74 μmol·L^-1 to 1.58 μmol·L^-1.