New triterpene glycosides from the roots of Securidaca longepedunculata

In the field of our research on saponins from African medicinal plants belonging to the Polygalaceae family, Securidaca longepedunculata Fres. was investigated. This species was collected in Democratic Republic of Congo, and is traditionally used in the African folk medicine for the treatment of diarrhea, cough, fever, bronchitis, inflammation, snakebite, and leprosy [1]. Pharmacological studies have shown its antimicrobial, antinociceptive and antidepressive properties in the mouse [2,3].

From a crude saponin mixture, 4 new triterpene saponins were isolated by several steps of solid/liquid chromatographic methods, and their structure were determined mainly by 600MHz 2D NMR techniques and mass spectrometry. From a chemotaxonomic point of view, the four new molecules isolated presented the same sequence 3-O-(ß-D-glucopyranosyl)presenegenin 28-O-ß-D-xylopyranosyl-(1→4)-O-α-L-rhamnopyranosyl-(1→2)-O-ß-D-fucopyranosyl) ester. This result corroborates the literature data about the structures of the saponins isolated from various plants of the Polygalaceae family [4].

References: 1. Delaude, C. 1992 Bull. Soc. Roy. Sc. Liège 61:245; 2. Ajali, U. et al. 2004 Phytomedicine 11:701–703; 3. Adebiyi, R.A. et al. 2006J. Ethnopharmacol. 107:234–239; 4. Lacaille-Dubois, M.-A. et al. 2005 Phytochemistry Reviews 4:139–149.