Phytochemical studies on Astragalus wiedemannianus Fischer
Makaleler > Tam Makale · 2009
Yazarlar: Erdoğan POLAT, E Bedir, A Perrone, S Piacente, SG Şenol, 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 a new and four known triterpene glycosides from methanolic extract of A. wiedemannianus by combined chromatografies on reverse phase C-18 and silica gel. The structure of the new compound was determined as 20( R ),24( S )-3- O -[α-L-rhamnopyranosyl(1→2)-β-D-glucopyranosyl]-25- O -β-D-glucuronopyranosyl-3β,6α,16β,25-tetrahydroxy-cycloartane by a combination of one- and two-dimensional NMR techniques, and mass spectrometry. The known saponins were identified as cycloastragenol, astragaloside IV, astragaloside VIII, and cycloascauloside B by spectral data and comparison of their physical properties with those reported previously for these compounds [5–7]. 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. [5] Kitagawa, I. et al. (1983) Chem. Pharm. Bull. 31:698–708. [6] Kitagawa, I. et al. (1983) Chem. Pharm. Bull. 31:716–722. [7] Alaniya, M.D. et al. (2008) Chem. Nat. Comp. 44:324–325.