The chemical constituents with cytotoxicity from Urtica fissa seed.

Phytochemical investigation of Urtica fissa seed led to the isolation of a new secolignan (1) and a new glycoalkaloid (2), together with 16 known compounds (3-18). The subsequent active evaluation indicated that two lignans (1, 12), two ceramides (3, 4), and the glycoalkaloid (2) possessed the significant cytotoxicity. They could obviously inhibit the proliferation of tumor cells HeLa and CCRF-CEM cells, with IC50 values as low as 1.5 μM.