Planta Med 2012; 78 - P_45
DOI: 10.1055/s-0032-1307553

Application of Centrifugal Preparative Chromatography for the Isolation of Polar Triterpenene Saponins from Fagonia cretica

M Zaki 1, 2, R Abd slam 2, M Hetta 2, I Muhammad 1
  • 1National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, Mississippi 38677, USA
  • 2Department of Pharmacognosy, School of Pharmacy, Beni-Suif University, Beni-Suif, Egypt

Fagonia cretica (Fam. Zygophyllaceae) is a shrub widely distributed in the Mediterranean regions, including Egypt, and is used in traditional medicine as a remedy for skin lesion. This plant is reported to contain saponins, which display a wide range of biological activities including anti-inflammatory, antimicrobial, and antitumor activities. These biological activities led us to investigate saponins of Fagonia cretica. An EtOH extract of the aerial parts of this plant was subjected to centrifugal thin layer chromatography (CPTLC), using a Chromatotron instrument, with a silica gel disc. The separation yielded hederagenin-3-O-α-L-arabinopyranosyl-28-O-β-D-glucopyranoside (1) and a mixture of two saponins (2 and 3) with identical Rf values. Subsequently, the complex mixture of saponin glycosides 2 and 3 was separated by a customized reversed-phase CPTLC disc [1]. These customized discs provided a fast and economical method for the preparative isolation of polar natural products, where there are difficulties with separation using traditional silica gel or RP C18 column chromatography. Compounds 2 and 3 were characterized using 1D and 2D NMR spectral data as hederagenin-3-O-β-D-xylopyranosyl(1→2)-α-L-arabinopyranosyl-28-O-β-D-glucopyranoside (2) and oleanolic acid 3-O-β-D-glucopyranosyl(1→2)-α-L-arabinopyranosyl-28-O-β-D-glucopyranoside (3). The application of centrifugal (or radial) chromatography for the isolation of compounds 1-3 and their structure elucidation, will be discussed in this presentation.

1 R1=ara; R2=OH; R3=glu
2 R1=ara(2→1) xyl; R2=OH; R3=glu
3 R1=ara(2→1) glu; R2=H; R3 =glu

Acknowledgements: MA Zaki would like to acknowledge the Ministry of Higher Education, Egypt, for awarding a scholarship. This work is partially supported by USDA ARS cooperative agreement No. 58–6408–2-0009 References: [1] Ilias M, Samoylenko V, et al. Chromatoplate Provisional Patent No. 61/532, 649, 2011.