The C25-quassinoids 20(R)- and 20(S)-simarolide were isolated from Simaba cuneata, Simaroubaceae. The structures of these two compounds were characterized by spectral data, including 1D and 2D NMR spectra which were also used for the complete assignment of the carbon and hydrogen atom chemical shifts.
Simaba cuneata; Simaroubaceae; C25-quassinoids