LAUSR

Abstract Phytochemical investigations from the roots of Cynanchum stauntonii led to obtain four new C 21 steroidal glycosides ( 1 – 4 ) and one known compound stauntoside F ( 5 ). Their chemical structures were characterized by sophisticated analyses of IR, HRESI-TOF-MS, 1D, and 2D-NMR data, together with chemical methods, which showed interesting 13,14:14,15-disecopregnane-type skeleton or 14,15-secopregnane-type skeleton C 21 steroidal glycosides. Among them, compound 1 was determined to be glaucogenin C 3- O - β - d -glucopyranosyl-(1 → 4)- β - d -cymaropyranosyl-(1 → 4)- β - d -digitoxopyranosyl-(1 → 4)- β - d -thevetopyranoside. Compound 2 was characterized to be hirundigenin 3- O - α - l -diginopyranosyl-(1 → 4)- β - d -cymaropyranosyl-(1 → 4)- β - d -digitoxopyranosyl-(1 → 4)- β - d -3′-demethyl-thevetopyranoside. Compound 3 was identified to be (14 S ,16 S ,20 R )-14,16-14,20-15,20-triepoxy-14,15-secopregn-5-en-3-ol-3- O- α- l -cymaropyranosyl-(1 → 4)- β - d -digitoxopyranosyl-(1 → 4)- β - d -oleandropyranoside. Compound 4 was identified to be (14 S ,16 S ,20 R )-14,16-14,20-15,20-triepoxy-14,15-secopregn-5-en-3-ol-3- O - α - l -cymaropyranosyl-(1 → 4)- β - d -cymaropyranosyl-(1 → 4)- β - d -digitoxopyranosyl-(1 → 4)- β - d -thevetopyranoside. Among them, compound 2 was hirundigenin type C 21 steroidal glycoside that existed in nature as epimers due to the presence of 14-hemiketal hydroxyl group in its structure. In addition, the anti-inflammatory and cardiomyocyte protective effects of compounds 1 – 4 were evaluated. We found that they exhibited significant protective effects on hypoxia/reoxygenation induced cardiomyocyte injury, but did not showed obvious anti-inflammatory function.