Immunostimulatory 6/6/6/6 Tetracyclic Triterpenoid Saponins with the Methyl-30 Incorporated Cyclization from the Root of Colquhounia elegans

Two novel triterpenoid saponins, colqueleganoids A (1) and B (2), with the first methyl-30 incorporated 6/6/6/6-cyclized carbon skeleton (named colquelegane), were isolated from the root of Colquhounia elegans. Their structures including absolute configuration were determined by spectroscopic methods and X-ray crystallographic analyses. Interestingly, both compounds significantly enhanced TNF-alpha production and 1 also increased the IL-6 production in RAW264.7 macrophages stimulated with lipopolysaccharide (LPS), suggesting their potential application as immunostimulants in immunotherapy and vaccination.

Automated summary

Two novel triterpenoid saponins, colqueleganoids A and B, were isolated from the root of Colquhounia elegans, featuring a unique carbon skeleton colquelegane with methyl-30. These compounds were found to significantly enhance TNF-alpha production and IL-6 production in RAW264.7 macrophages stimulated with lipopolysaccharide, suggesting their potential as immunostimulants for immunotherapy and vaccination.