Studies on the constituents of Cyclanthera pedata fruits:: Isolation and structure elucidation of new triterpenoid saponins

The isolation of nine triterpenoid saponins (1-9), among them six new natural compounds (1-6), from the MeOH extract of the fruits of Cyclanthera pedata is reported. All of the structures were elucidated by spectroscopic methods, including the concerted application of one-dimensional H-1-H-1 total correlation spectroscopy, H-1-H-1 nuclear Overhauser effect spectroscopy), and C-13-C-13; DEPT-NMR and two-dimensional NMR techniques (double-quantum filtered correlated spectroscopy, rotating-frame Overhauser enhancement spectroscopy, heteronuclear single quantum coherence, and heteronuclear multiple bond correlation). A comparative study of seeds and fruits has been also carried out.