Two secopregnane-type steroidal glycosides from Cynanchum stauntonii (Decne.) Schltr.ex Levl

• Published in: Phytochemistry letters 2012-06, Vol.5 (2), p.304-308
• Main Authors: Shibano, Makio, Misaka, Ayaka, Sugiyama, Kayoko, Taniguchi, Masahiko, Baba, Kimiye
• Format: Article
• Language: English
• Subjects: Asclepiadaceae; Cynanchum; Cynanchum stauntonii; inhibitory concentration 50; Na+/K+-ATPase inhibitor; ouabain; Secopregnane type steroid
• ISSN: 1874-3900; 1876-7486
• DOI: 10.1016/j.phytol.2012.02.007

[Display omitted] ► This study reports on isolation of two new steroid glycosides (1 and 2) from the roots extract of Cynanchum stauntonii (Decne.) Schltr.ex Levl. ► Their structures were elucidated on the basis of 1D- and 2D-NMR, mass, IR and UV spectroscopic analyses. ► Na+/K+-ATPase inhibitory activity was tested for 1 and 2, and they showed moderate activity. Two new steroid glycosides, stauntosaponins A (1) and B (2), were isolated from Cynanchum stauntonii (Decne.) Schltr.ex Levl. (Asclepiadaceae) together with five known compounds, anhydrohirundigenin monothevetoside, glaucogenin C mono-d-thevetoside, hirundoside A, cynatratoside A, and glaucogenin C. Stauntosaponins A and B were formulated as 3-O-β-d-oleandropyranosyl-14, 16: 15, 20: 18, 20-triepoxy-14, 15-secopregn-4, 6, 8(14)-triene (1) and 3-O-β-d-thevetopyranosyl-14, 16: 15, 20: 18, 20-triepoxy-14, 15-secopregn-4, 6, 8(14)-triene (2). Compounds 1 and 2 showed moderate inhibitory activities against Na+/K+-ATPase with IC50 values of 21 and 29μM, respectively, whereas ouabain as a positive control displayed an IC50 value of 3.5μM.