Ramifloraolides A - D, four highly oxygenated picrotoxane-type sesquiterpenoids from the stems of Baccaurea ramiflora and their antithrombotic activity.

A phytochemical investigation of the ethanol extract from air-dried stems of Baccaurea ramiflora led to the isolation of four highly oxygenated picrotoxane-type sesquiterpenoids, ramifloraolides A - D (1-4). Their structures were elucidated by comprehensive spectroscopic data (HRESIMS, IR, 1D, and 2D NMR), and their absolute configuration of them were unambiguously determined by single-crystal X-ray diffraction. Structurally, all compounds possess a unique [4.