Chemical Constituents of Lecythispisonis (Lecythidaceae)--A New Saponin and Complete 1H and 13C Chemical Shift Assignments.

A novel triterpenoid saponin 3-O-ß-D-glucuronopyranosyl-(1' --> 3)-2α,19α-dihydroxyolean-12-en-28-oic acid [3-O-ß-D-glucuronopyranosyl-(1' --> 3)-arjunic acid, 1], ten known compounds [six triterpenoids: α-amyrin (2), ß-amyrin (3), germanicol (4), lupeol (5), friedelin (6), friedelanol (7); four steroids--campesterol (8), stigmasterol (9), sitosterol (10), cholesterol (11)], and a long chain alcohol n-eicosan-1-ol (12) were identified in the bark of Lecythis pisonis. The structures were established by 1D and 2D NMR spectroscopy (1H and 13C-NMR, DEPTQ, 1H-1H-COSY, NOESY, HSQC and HMBC), low (CG-MS) and high resolution mass spectrometry (HR-ESI-MS), and infrared (IR) spectral data involving comparison with the literature.