Cyclovibsanins, Unprecedented Seven-Membered Vibsane-Type Diterpenes from Viburnum awabuki

Abstract

Four unprecedented vibsane-type diterpenes, named cyclovibsanin A, 15-Omethylcyclovibsanin A, 15-O-methylcyclovibsanin B, and 3-hydroxy-15-O-methylcyclovibsanin A, were isolated from the leaves of Viburnum awabuki. Their unique tricyclo[6.3.2.00,0]tridecane structures and plausible biosynthesis of cyclovibsanins are discussed here. Keywords: vibsane-type diterpene, cyclovibsanin, seven-membered vibsane, viburnum awabuki