Cytotoxic triterpenoid saponins from Symplocos chinensis

Six new triterpenoid saponins were isolated as methyl or butyl esters from an n-BuOH extract of the roots of Symplocos chinensis. Their structures were established as symplocososides A (1), B (2), C (3), D (4), E (5), and F (6), by extensive 1D and 2D NMR as well as HR-MS analysis and chemical methods. Compounds 1, 3, and 6 were cytotoxic against one or more cell lines, and the derivative from 1 (1d) showed significant selectivities between KB cells and normal cells.