Two original oleanane-type triterpenoid saponins, tunicosaponin A (TSA) and tunicosaponin E (TSE) were isolated from the roots of Psammosilene tunicoides. Four semi-synthetic saponin derivatives, TSA1, TSA2, TSA3, and TSA4, were synthesized from TSA; two derivatives TSE1 and TSE2 were prepared from