Four new diterpenoid alkaloids with anti-inflammatory activities from Aconitum taronense Fletcher et Lauener

Four new C-19-diterpenoid alkaloids, named taronenines A-D (1-4), have been isolated from the roots of Aconitum taronense Fletcher et Lauener (Ranunculaceae), which has long been used as a folk medicine to treat rheumatism and arthritis in China. Their structures were established on the basis of extensive spectroscopic analyses. The isolated compounds were evaluated for their potential anti-inflammatory effects using LPS-stimulated RAW 264.7 macrophages. Compounds 1, 2 and 4 showed certain inhibition activities of interleukin-6 in LPS-activated RAW 264.7 cells with IC50 values of 29.60 +/- 0.08 mu g/mL, 18.87 +/- 0.14 mu g/mL, and 25.39 +/- 0.11 mu g/mL, respectively.