A new cycloartane-type glycoside from Astragalus schottianus Boiss

Astragalus L., the largest genus in the family Leguminosae, is represented by 445 species, of which 224 are endemic. They can be attributed to 62 sections in the flora of Turkey [1,2,3]. The roots of Astragalus species represent a very old and well-known drug in traditional medicine for its usage as an antiperspirant, diuretic and tonic drug [4]. In the district of Anatolia, located in South Eastern Turkey, an aqueous extract of the roots of Astragalus is traditionally used against leukemia and for its wound-healing properties. Known biologically active constituents of Astragalus roots represent two major classes of chemical compounds, polysaccharides and saponins [4].

In our continuing search on Turkish Astragalus species, we have isolated a new cycloartane-type triterpene glycoside from methanolic extract of A. schottianus by combined chromatography on reverse phase C-18 and silica gel. The structure of the new compound was determined as 3-O-β-D-xylopyranosyl-3β,6α,16β,20(S),24(S),25-hexahydroxycycloartane by the extensive use of 1D and 2D-NMR techniques and mass spectrometry. This compound represents the first entry of the series of cycloartane-type compound possessing a 20-OH functional group in Astragalus genus.

Figure 1

References: 1. Davis PH (1978) Flora of Turkey and East Aegean Islands Vol.4, University Press: Edinburg.

2. Güner A, Ozhatay N, Ekim T, Başer KHC (2000), Flora of Turkey and the East Aegean Islands Vol.11, University Press: Edinburg.

3. Özüdoğru B et al. (2011) Ann Bot Fennici 48: 1797–2442.

4. Tang W, Eisenbrand G (1992) Chinese Drugs of plant Origin, Springer-Verlag: Berlin.