C19-diterpenoid alkaloids from Aconitum refractum var. circinatum

Two unprecedented aconitine-type C19-diterpenoid alkaloids, refractines A–B (1–2), along with 12 known compounds (3–14) were isolated from the roots of Aconitum refractum (Finet et Gagnep.) Hand. -Mazz. Their structures were elucidated based on extensive spectroscopic analyses, including 1D and 2D NMR, IR, and HR-ESI-MS data. All compounds were tested for inhibitory activities against NO production in LPS induced RAW 264.7 macrophages, compounds 10 and 14 had slight inhibited NO production with rate of 29.4% and 22.1% at the concentration of 30 μM, respectively.