New cycloartane-type glycosides from Astragalus icmadophilus Hand.-Mazz.
Makaleler > Tam Makale · 2009
Yazarlar: İ Horo, E Bedir, A Perrone, S Piacente, F Özgökçe, Özgen ALANKUŞ
Planta Medica, Uluslararası, Wos, 2009, cilt 75
Özet
Astragalus L., the largest genus in the family Leguminosae, is represented by 380 species in the flora of Turkey [1]. 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 [2]. Known biologically active constituents of Astragalus roots represent two major classes of chemical compounds, polysaccharides and saponins [2]. Our earlier investigations performed on Astragalus species resulted in the isolation of a series of cycloartane-type triterpenic saponins [3,4]. In our continuing search on Turkish Astragalus species, we have isolated four new and five known triterpene glycosides from methanolic extract of A. icmadophilus by combined chromatografies on reverse phase C-18 and silica gel. The structures of the new compounds were determined as 3- O -[α-L-arabinopyranosyl(1→2)-3′-O-acetyl-β-D-xylopyranosyl]-6- O -β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxy-cycloartane, 3- O -[α-L-rhamnopyranosyl(1→2)-α-L-arabinopyranosyl(1→2)-β-D-xylopyranosyl]-6- O -β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxy-cycloartane, 20(R),25-epoxy-3- O -[α-L-arabinopyranosyl(1→2)-β-D-xylopyranosyl]-6- O -β-D-glucopyranosyl-3β,6α,16β,24α-tetrahydroxy-cycloartane, 20(R),25-epoxy-3- O -[α-L-rhamnopyranosyl(1→2)-α-L-arabinopyranosyl(1→2)-β-D-xylopyranosyl]-6- O -β-D-glucopyranosyl-3β,6α,16β,24α-tetrahydroxy-cycloartane by a combination of one- and two-dimensional NMR techniques, and mass spectrometry. References: [1] Davis, P.H. (1978) „Flora of Turkey and East Aegean Islands“ Vol.3, University Press: Edinburgh. [2] Tang, W., Eisenbrand, G. (1992) „Chinese Drugs of Plant Origin“ Springer-Verlag, Berlin. [3] Bedir, E. et al. (1999) Phytochem. 51:1017–1020. [4] Bedir, E. et al. (1999)J. Nat. Prod. 62:563–568.