An Immune-suppressive Triterpenoid from the Stem of Kadsura coccinea

Kadsura coccinea has been used as a folk medicine in China, treating various diseases, including chronic gastritis and rheumatoid arthritis (RA). Chemical studies have revealed that lignans and triterpenes are the main constituents of its roots and stems. In this paper, a chemical investigation on the stem of K. coccinea was performed and a previously undescribed 3,4-secolanostane (1) was afforded. The structure of 1 was determined through comprehensive NMR and HRESI-MS data analysis. The stereo-configuration of 1 was established based on a comparison of experimental and calculated ECD spectra. Bioactivity assay carried out in immune cells indicated that 1 could show moderate effects on ConA (5 μg/mL)-induced T-cell proliferation with an IC50 value of 13.28 μM (cyclosporine A as the positive drug, IC50 = 0.13 μM) while the IC50 value was 23.12 μM in LPS (10 μg/mL)-induced B cells (mycophenolate mofetil as the positive drug, IC50 = 16.71 μM).