Navicularines A-C: New diterpenoid alkaloids from Aconitum naviculare and their cytotoxic activities.

Three new bisditerpenoid alkaloids, navicularines A-C (1-3), and three known ones (4-6), were isolated from the ground parts of Aconitum naviculare. Their structures were elucidated by spectroscopic methods. All the new compounds were tested against five cell lines (HL-60, SMMC-7721, A-549, MCF-7, SW480). It was found that navicularine B exhibited certain cytotoxic activities in vitro, with IC50 values of 13.50, 18.52, 17.22, 11.18, and 16.36µM, respectively.