Calamus leptospadix Griff. a high saponin yielding plant with antimicrobial property

• Calamus leptospadix Griff. is an ethnomedically important plant yielding 9.5% of saponin which can be a novel source for saponin production.
• The saponin was identified as ursolic acid (3-beta-3-hydroxy-urs-12-ene-28-oic-acid) type triterpenoid saponin.
• Saponin isolated from C. leptospadix was found to possess antibacterial and antifungal activity, which make this plant medicinally important.

There are many scientifically unrevealed plant species in the Sub-Himalayan region, which have been used by the local tribes for their day-to-day use. Calamus leptospadix Griff. is a non-climbing palm predominantly found in North-East India. The objective of this study is to isolate and identify saponin extracted from tender shoots of C. leptospadix and the determination of its antimicrobial activity. In the present investigation, the total saponin content was found to be 9.5% when the tender shoots were extracted in methanol followed by n-butanol. Saponin isolated from C. leptospadix was further characterized by HPLC, FT-IR, 1H NMR and 13C NMR which confirm the presence of only one type of ursolic acid (3-beta-3-hydroxy-urs-12-ene-28-oic-acid) which is a triterpenoid saponin with olefinic carbon at C-12 and C-13. Antimicrobial properties of the isolated saponin were tested by disc diffusion method and by determining the minimum inhibitory concentration (MIC). Lowest MIC was found to be 60 μg/ml for Escherichia coli and Candida albicans. The minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) for E. coli and C. albicans were recorded at 140 μg/ml and 120 μg/ml respectively. Highest MIC of 160 μg/ml was recorded for Staphylococcus aureus. This study showed that shoots of C. leptospadix contains a significant amount of saponin, which was confirmed as ursolic acid type of triterpenoid saponin with antimicrobial properties.