Structure determination of bitter principles of Ailanthus altissima. Structures of shinjulactones F,I,J, and K.

Four new quassinoids, shinjulactones F, I, J, and K were isolated from Ailanthus altissima SWINGLE. The structure of shinjulactone F was established to be 1α,11-epoxy-1β,20-dihydroxy-5βH-picrasa-3,9(11)-diene-2,12,16-trione by X-ray diffraction analysis. The structures of shinjulactones I, J, and K were determined to be 11α-acetoxy-2α, 12α-dihydroxypicrasane-1,16-dione, 1β,12β-dihydroxypicrasane-2,11,16-trione, and 12α-acetoxy-2α,11α-dihydroxypicrasane-1,16-dione, respectively, by spectral and chemical means.