Planta Med 2011; 77 - PG47
DOI: 10.1055/s-0031-1282531

Flavonoid triglycosides from Astragalus armatus

A Khalfallah 1, A Karioti 2, D Berrehal 1, A Kabouche 1, M Lucci 3, Z Kabouche 1, A Bilia 2
  • 1Laboratoire d'Obtention de Substances Thérapeutiques (LOST), Faculté des Sciences, Université Mentouri – Constantine, Campus Chaabet Ersas, 25000 Constantine, Algeria
  • 2Department of Pharmaceutical Sciences, University of Florence, Ugo Schiff 6, 50019, Sesto Fiorentino (FI), Italy
  • 33 Magnetic Resonance Center, Via Luigi Sacconi 6, 50019 Sesto Fiorentino (FI), Italy

Astragalus armatus Willd. is an endemic shrub of the Northern Africa (Algeria, Morocco, Tunisia), is distributed in the pre-Saharian zone and is associated with the desertification in arid areas due to overgrazing [1]. In Tunisia it is used as tonic, stimulant and in cases of anaemia [2]. From the aerial parts of A. armatus a new acylated flavonoid triglycoside, isorhamnetin-3-O-(4'''-p-hydroxybenzoyl)-α-apiofuranosyl-(1→2)[α-rhamnopyranosyl-(1→6)]-β-galactopyranoside (1), and one new flavonoid triglycoside, tamarixetin-3-O-α-apiofuranosyl-(1→2)[α-rhamnopyranosyl-(1→6)]-β-glucopyranoside (2), have been isolated together with six known flavonoids: isorhamnetin-3-O-α-apiofuranosyl-(1→2)[α-rhamnopyranosyl-(1→6)]-β-galactopyranoside, kaempferol-3-O-α-rhamnopyranosyl-(1→2) [α-rhamnopyranosyl-(1→6)]-β-glucopyranoside, kaempferol-3-O-α-rhamnopyranosyl-(1→2)[α-rhamnopyranosyl-(1→6)]-β-galactopyranoside, isorhamnetin-3-O-α-rhamnopyranosyl-(1→2)[α-rhamnopyranosyl-(1→6)]-β-galactopyranoside, nikotiflorin and narcissin. The structures of the isolated compounds were established by means of 2D NMR, HPLC-DAD-MS, HR-MS, and UV spectral analyses. Pivotal role in the structure elucidation and in particular in the determination of the sugar sequence, played ROESY and HSQC-TOCSY experiments.

Figure 1: Structures of the new naturally occurring compounds

Acknowledgement: The authors are grateful to ANDRS and DG-RSDT (MESRS, Algeria) for financial support and to Prof. Gérard De Bélair (Faculty of Sciences, University Badji-Mokhtar-Annaba) for the identification of the plant material and to Dr. Elena Michelucci (Mass Spectrometry Center, University of Florence – CISM) for recording the HRESI mass spectra. The authors would like to thank Stefano Rocchi for technical assistance

References: 1. Hirche A et al. (2010) Environ Monit Assess DOI 10.1007/s10661–010–1744–5

2. Bouaziz et al. (2009) Afr J Biotechnol 8: 7017–7027.