N-Containing triterpenoid saponins from Mussaenda densiflora and identification of heinsiagenin A as a potent immunosuppressant

Bioorg Chem. 2024 Apr 6;147:107351. doi: 10.1016/j.bioorg.2024.107351. Online ahead of print.

ABSTRACT

Eleven triterpenoid saponins, including five new compounds, which were named densiflorasides A - E (1 - 5), were isolated from aerial parts of Mussaenda densiflora (Rubiaceae). Their structures were elucidated based on spectroscopic and single-crystal X-ray diffraction analyses and chemical methods. All the isolated compounds and the aglycone heinsiagenin A were evaluated for their immunosuppressive and antiosteoclastogenic activities in vitro. Compounds 6 - 8 and heinsiagenin A inhibited osteoclastogenesis, with IC₅₀ values ranging from 8.24 to 17.7 µM. Furthermore, compounds 3, 6 - 8, and heinsiagenin A significantly inhibited T-cell proliferation, with IC₅₀ values ranging from 2.56 to 8.60 µM, and compounds 3 - 5 and 11 inhibited the proliferation of B lymphocytes, with IC₅₀ values ranging from 1.29 to 8.49 µM. Further in vivo experiments indicated that heinsiagenin A could significantly attenuate IMQ-induced psoriasis and DSS-induced colitis in mice.

PMID:38593530 | DOI:10.1016/j.bioorg.2024.107351