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 (1)H-(1)H total correlation spectroscopy, (1)H-(1)H nuclear Overhauser effect spectroscopy), and (13)C-(13)C 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.