3-Oxo-11β-hydroxyfriedelane from the roots of Celastrus monospermus

A new friedelane type triterpene, 3-oxo-11 beta-hydroxyfriedelane, named as monospermol, was isolated from the roots of Celastrus monospermus Roxb.(Celastraceae) along with seven known compounds friedelin, 3,12-dioxofriedelane, 3-oxo-28-hydroxyfriedelane, 3-oxo-12 alpha-hydroxyfriedelane, beta-sitosterol, pristimerin and celastrol. Structural formula and the stereochemistry of the new friedelane type triterpene 1 were established through (1)H NMR and (13)C NMR spectral data including 2D experiments (HMBC, HSQC, (1)H-(1)H COSY and NOESY) and high resolution mass spectrometry.