Evaluation of novel saponins from Psammosilene tunicoides and their analogs as immunomodulators

► TSA and TSE were found in the roots of Psammosilene tunicoides for the first time. ► Six semi-synthetic saponins were derived from TSA and TSE. ► TSA2 should be further explored as an immunomodulator for immune responses. ► The hydrophobicity of obtained chains is critical for toxicity and adjuvant.