Rubupungenosides A and B, two novel triterpenoid saponin dimers from the aerial parts of Rubus pungens.

Two new triterpenoid saponin dimers, rubupungenosides A (1) and B (2), were isolated in their methylated forms 1a and 2a, respectively, from an ethanol extract of the aerial parts of Rubus pungens. The structures of 1a and 2a were established on the basis of spectroscopic and chemical methods.