Eight new cafestol-type diterpenoids, tricalysins A-H (1-8), along with five known analogues (9-13), were isolated from the twigs of Tricalysia fruticosa. The structures of 1-8 were elucidated by the application of spectroscopic methods. Inhibitory effects of the isolates on nitric oxide (NO)
Four rearranged ent-kaurane diterpenoid alkaloids, tricalysiamides A-D (1-4), having a cafestol-type carbon framework were isolated from the wood of Tricalysia dubia. Their absolute structures were determined on the basis of 2D NMR spectroscopy, X-ray crystallographic analysis, and chemical methods.