Isolation and characterization of seven neovibsane-type diterpenoids from Viburnum odoratissimum and their neuroblastoma cell protective effects

Abstract

Seven undescribed neovibsane-type diterpenoids (1-7) were isolated from the leaves of Viburnum odoratissimum. Their planar structures and relative configurations were elucidated based on a combination of 1D and 2D NMR analysis. The absolute configurations were confirmed by Rh₂(OCOCF₃)₄-induced ECD analysis and comparison of experimental and TDDFT-calculated ECD spectrum. Based on the empirical results of the ECD of in situ formed Rh-complexes, rapid determination of the absolute configuration of C-14 within vibsane-type diterpenoids was proposed. In addition, 3 exhibited a high neuroblastoma cell protective effect of 81.8 % at 50 μM (the control group showed a neuroblastoma cell protective effect of 56.2 % at 50 μM).

Keywords: Diastereomers; Neovibsane-type diterpenoids; Neuroblastoma cell protective effect; Viburnaceae; Viburnum odoratissimum.