Vibsatins A and B, Two New Tetranorvibsane-Type Diterpenoidsfrom Viburnum tinuscv. variegatus.

Vibsatins A (1) andB (2), a pair of14,15,16,17-tetranorvibsane-type diterpenoids that feature a bicyclo[4.2.1]nonanemoiety formed by a new C-13/C-2 bond, were isolated from the twigsand leaves of Viburnum tinuscv. variegatus. Thestructures and absolute configurations were elucidated by a combinationof NMR spectra, optical rotation, and X-ray diffraction experiments.A possible biogenetic pathway is also proposed. Moreover, vibsatinA (1) enhanced the neurite outgrowth of NGF-mediatedPC12 cells at a concentration of 10 μM. [ABSTRACT FROM AUTHOR]