Picrotoximaesins B-D, new picrotoxane-type sesquiterpenoids from the berries of Maesobotrya dusenii (Pax) Hutch

The phytochemical investigation of the methanolic berry extract of Maesobotrya dusenii has led to the isolation and characterization of three novel picrotoxane-type sesquiterpenoids named picrotoximaesins B-D (2-4) alongside with five known compounds. The structures of the compounds were determined by analyses of their spectroscopic (1D and 2D NMR) and spectrometric (HRMS) data in conjunction with literature records. The relative configurations were established by the biosynthetic pathway of picrotoxane-type sesquiterpene, comparison with analogues described in the literature and by using their NOESY spectra.