Planta Med 2010; 76 - P550
DOI: 10.1055/s-0030-1264848

Two new cycloartane glycosides from Astragalus cicer L. (Fabaceae)

J Linnek 1, A Mitaine-Offer 2, T Miyamoto 3, T Paululat 4, M Lacaille-Dubois 5
  • 1University of Burgundy, Faculty of Pharmacy, Laboratory of Pharmacognosy, EA 3660, 7, Bd Jeanne D'Arc, 21079 Dijon, France
  • 2University of Burgundy, Faculty of Pharmacy, Laboratory of Pharmacognosy, EA 3660, 7, Bd Jeanne D'Arc, 21079 Dijon, France
  • 3Kyushu University, Graduate School of Pharmaceutical Sciences, Maidashi Higashi Ku 3–1-1, 812–8582 Fukuoka, Japan
  • 4Universitaet Siegen, Department of Organic chemistry, Adolf-Reichwein-Strasse 2, 57968 Siegen, Germany
  • 5University of Burgundy, Faculty of Pharmacy, Laboratory of Pharmacognosy, EA 3660, 7, Bd Jeanne d'Arc, 21079 Dijon, France

The genus Astragalus contains more than 2000 species and represents one of the largest genus in the family of Fabaceae. It is widely distributed in the world of which about 70 species have been found in the Mediterranean region [1]. Some of them are well-known for their pharmacological properties, particularly hepatoprotective, immunostimulant and antiviral activities [2]. Many phytochemical studies on Astragalus genus were realized bringing out the presence of saponins with cycloartane-type genins [1,3]. Meanwhile no phytochemical investigations have been made on Astragalus cicer L. In this study we present the isolation and structural elucidation of two new cycloartane-type saponins named cicerosides A and B (1,2) together with the known coumpound eremophiloside B [4] from the aerial parts of A. cicer L. The n-butanol fraction from the methanol extract of the aerial parts was submitted to several solid/liquid preparative chromatographic methods such as CC on Sephadex LH-20, flash chromatography and MPLC over normal and reversed phase RP18 silica gel. The structures were established mainly by 600MHz 1D and 2D NMR techniques (COSY, TOCSY, NOESY, HSQC, HMBC) and mass spectrometry. The structure of compound 1 was elucidated as 3β,6α,16β,24(R),25-pentahydroxycycloartan-3-yl-3-O-(α-Lrhamnopyranosyl)-6-O-(α-L-rhamnopyranosyl)-16-O-acetoxy-24-O-(β-D-glucopyranosyl)-25-O-β-D xylopyranoside, named ciceroside A and compound 2 as 3β,16β,24(R),25-tetrahydroxycycloartan-6-on-3-yl-3-O-(α-L-rhamnopyranosyl)-24-O-(β-D-glucopyranosyl)-25-O-β-D-xylopyranoside, named ciceroside B.

References: 1. Verotta, L. et al. (2001) Studies in Natural Products Chemistry. Elsevier. Amsterdam. 25:179–234.

2. Rios, JL. et al. (1997) Phytotherapy Res. 11:411–418.

3. Linnek, J. et al. (2009) Nat. Prod. Comm. 4:477–478.

4. Peronne, A. et al. (2008) Tetrahedron 64:5061–5071.