Three new diterpenoid alkaloids from Delphinium trichophorum

Three previously unreported diterpenoid alkaloids were isolated from the ethanol extract of Delphinium trichophorum Franch and named trichophinines A-C (1-3), along with twenty-four known compounds. Compounds 1 and 2 were lycoctonine-type C₁₉-diterpenoid alkaloids, while compound 3 was a hetisine-type C₂₀-diterpenoid alkaloid. Their structures were delineated on the basis of spectroscopic analyses, including IR, HR-ESI-MS, 1D and 2D NMR analyses. Compounds 1-3 were assessed for the inhibitory activities against LPS-induced NO production in RAW 264.7 macrophage cells, and none exhibited inhibitory activity.