Vibsane-type diterpenes from Taiwanese Viburnum odoratissimum

Two new eleven-membered and three new seven-membered vibsane-type diterpenes, named vibsanin L (1) and 14-hydroxyvibsanin F (2), and vibsanin I (3), 14R*,15-epoxyvibsanin C (4) and 14S*,15-epoxyvibsanin C (5) respectively, have been isolated from Viburnum odoratissimum collected in Taiwan. Their structures have been elucidated by spectroscopic analyses and comparison of Nuclear magnetic resonance method (NMR) data with those of the previously reported vibsane-type diterpenes. High performance liquid chromatography (HPLC) analyses indicated that the methanol extract of V. odoratissimum collected in Taiwan contained no neovibsanines, characteristic chemicals occurring in V. awabuki.