Spirostane-type saponin

Twenty nine steroidal saponins have been evaluated for their inhibitory effects on human spermatozoa motility in vitro according to a modified Sander-Cramer method [233]. Spirostane-type saponins have stronger inhibitory activities than those of furostane-type. The carbonyl group at C-12 and the double bond A (5,6) of the aglycone were important for the activity. The monodesmosidic saponin, diuranthoside B from Diuranthera major appeared the most active (motility of 45% at 0.1 mg/ml), almost equivalent to the commonly used spermicidal agent N-9. These results indicated the possibility of discovering natural spermicidal agents from steroidal saponins. Further work on the cytotoxic activity of these compounds are underway. 

Harmatha, j., B. Mauchamp, C. Arnault, and K. Slama, Identification of a spirostane-type saponin in the flowers of leek with inhibitory effects on growth of leek-moth larvae, Biochem. Syst. Ecol., 15, 113-116 (1987). 

C NMR spectrometry is also very helpful in assignment of stereochemistry at C-25 (R/S) of spirostane type steroidal saponins and sapo-genins. Agarwal et al. (138) have studied in detail the carbon resonances of smilagenin and sarsasapogenin using DEPT, COSY, TOCSY, HETCOR,... 

Agrawal PK (2003) Spectral Assignments and Reference Data 25R/25S Stereochemistry of Spirostane-Type Steroidal Sapogenins and Steroidal Saponins via Chemical Shift of Geminal Protons of Ring-F. Magn Reson Chem 41 965... 

Steroidal saponins (those based on C27-steroidal sapogenins) are found in a large number of plant families, but are particularly common in the monocotyledonous families Agavaceae, Amaryllidaceae, Dioscoreaceae, and Liliaceae (Dahlgren et al., 1981). The vast majority of steroidal saponins are based on furostan- or spirostan-type precursors (Hostettman et al., 1991). A series of steroidal saponins from... 

Yoshikawa M, Xu F, Morikawa T, Pongpiriyadacha Y, Nakamura S, Asao Y et al (2007) Medicinal flowers. XII. New spirostane-type steroid saponins with antidiabetogenic activity from Borassus flabellifer. Chem Pharm Bull 55 308-316... 

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