New Diterpenoids from Viburnum awabuki

Eight new vibsane-type diterpenoids, vibsanins P-W (1-8), were isolated from the methanol extracts of the leaves and twigs of Viburnum awabuki. The structures were elucidated by 1D and 2D NMR spectral analysis, and their cytotoxicity against selected cancer cells was measured in vitro.