Biologically Active Saponin from Seeds of Allium Ampeloprasum

A novel oleanen type triterpenoid glycoside has been isolated from the butanolic extract of the seeds of Allium ampeloprasum. Its structure was elucidated as 3?O?{??D?glucopyranosyl?(1?6)?[??L?rhamnopyranosyl?(1?2)]???D?glucopyranosyl?(1?4)?[??D?glucopyranosyl?(1?2)]???D?xylopyranosyl}?2,16?dihydroxy?23,29?dihydroxymethylolean?11,13(18)?diene?28?oic acid on the basis of spectral evidences, i.e. FT?IR, 1H NMR, 13C NMR and FAB?MS data. The isolated saponin was tested for its antimicrobial activity.  Significant results were obtained by evaluating the antibacterial activity by “Disc diffusion method” and antifungal activity by “Spore  dilution  method”.  Maximum  inhibition  was  recorded  in  gram  positive  bacterium? Streptococcus  pneumoniae,  while  complete  inhibition  on  the  growth  of  fungus?Alternaria alternata was observed at a concentration of  200  ?g/mL. The potency of the extract was quantitatively assessed by determining the minimum inhibitory concentration values against selected bacteria.  The minimum inhibitory concentration values were in agreement with antibacterial results where minimum value was recorded to be 23 ?g/mL for Streptococcus pneumonia. Key Words: Allium ampeloprasum, Triterpenoid, Saponin, Antimicrobial activity

A TRITERPENOID SAPONIN FROM THE SEEDS OF Ricinus communis AND ITS ANTIMICROBIAL ACTIVITY

A new oleanene triterpenoid was isolated from the butanolic seed extract of Ricinus communis. Its structure was elucidated as 3-O-[�-D-glucuronopyranosyl-(1�3)-�-L-rhamnopyranosyl-(1�2)�-D-glucopyranosyl]- 4�,20�-di(hydroxymethyl)olean-12-en-28-oic acid on the basis of spectral evidence i.e., FTIR, 1H and 13C NMR, and FAB-MS data. The isolated triterpenoid was found to have antimicrobial potential, viz. antibacterial and antifungal activity, where the growth of microbes was found to be an inverse function of the concentration of saponin. The MIC value for E. coli, Klebsiella pneumoniae and Staphylococcus aureus were found to be 260, 235, and 350 �g/mL