Four new C-21 steroidal glycosides from the roots of Stephanotis mucronata and their immunological activities

Four new C-21 steroidal glycoside, stemucronatosides D (1), E (2), F (3), and G (4) were isolated from the roots of Stephanotis mucronata. Their structures were determined on the basis of chemical evidence and extensive spectroscopic methods including one-dimensional and two-dimensional NMR. These isolated compounds were assayed for their immunological activities in vitro against concanavalin A (Con A)- and lipopolysaccharide (LPS)-induced proliferation of mice splenocytes. Compounds 1, 2, and 4 showed immunosuppressive activities in a dose-dependent manner, while compound 3 showed immunomodulating activities.