Nicotabaflavonoidglycoside, the first example of cembranoid and flavonoid heterodimer from Nicotiana tabacum.

Nicotabaflavonoidglycoside (1), a novel cembrane-type diterpenoid and flavonoid heterodimer had been isolated from the leaves of Nicotiana tabacum. Its structure was elucidated as (1″S, 6″S) or (1″R, 6″R)-8-[6″-((-)-(1″S, 2″E, 4″Z, 7″E, 11″E)-cembra-2″, 4″, 7″, 11″-tetraenyl)]-rutin by comprehensive analyses of the NMR and HRESIMS spectra. Its absolute configurations of C-1″ and C-6″ were assigned as (1″S, 6″S) by its biogenesis and electronic circular dichroism (ECD). A possible biogenesis involving eliminate reaction of (1S, 2E, 4S, 6R, 7E, 11E)-2, 7, 11-cembratriene-4, 6-diol or its 4R isomer, as well as electrophilic substitution reaction of rutin was postulated.