Planta Med 2008; 74 - PB101
DOI: 10.1055/s-0028-1084446

New saponins from the roots of Tocoyena formosa (Rubiaceae)

L Harmesky 1, C Carbonizi 1, AJ Cavalheiro 1, MCM Young 2, EM Cardoso-Lopes 2, LB Torres 2, VS Bolzani 1
  • 1Nuclei of Bioassays, Biosynthesis and Ecophysiology of Natural Products – NuBBE, São Paulo State University – UNESP – Chemistry Institute, Department of Organic Chemistry, Rua Prof. Francisco Degni s/n –14.800–900– Araraquara – São Paulo – Brazil
  • 2Seção de Fisiologia e Bioquímica de Plantas – Instituto de Botânica SMA/SP, Av. Miguel Stefano, 3687, 04301–012 São Paulo – SP – Brazil

Tocoyena formosa (Cham. et Sch.) K. Schun, popularly known as „genipapo do campo“, is a small ornamental tree that grows spontaneously in Brazilian Cerrado, a floristically and physiognomically diverse savanna vegetation [1]. In earlier communications, the isolation of iridoids from the leaves and stems of Tocoyenna formosa with antifungal properties, as well as the known triterpene saponin (3-O-β-D-glucopyranosyl-28-O-β-D-glucopyranosyl quinovic acid) has been reported [2,3]. In continuation of our studies with species of Rubiaceae family, the n-butanol soluble fraction of the ethanolic extract of the roots of T. formosa was chromatographed over Sephadex LH-20 and HPLC to yield five other triterpenoid saponins. Their structures were determined using a combination of homo- and heteronuclear 2D NMR techniques and HRESIMS and were established as 3-O-β-D-glucopyranosyl-(28→1)- β-D-glucopyranosyl quinovic acid (1) 3-O-β-D-glucopyranosyl-(2→1)-α-L-rhaminopyranosyl-(28→1)-β-D-glucopyranosyl quinovic acid (2), 3-O-β-D-glucopyranosyl-(2→1)-α-L-rhamnopyranosyl-(28→1)-β-D-glucopyranosyl chincolic acid (3), 3-O-β-D-glucopyranosyl-(1→4)-α-L-rhamnopyranosyl-(28→1)-β-D-glucopyranosyl quinovic acid (4) and 3-O-β-D-glucopyranosyl-(2→1)-α-L-rhamnopyranosyl-(28→1)-β-D-glucopyranosyl pomolic acid (5).

Acknowledgements: FAPESP, CNPq.

References: 1. Goodland, R.; Ferri, M.G. (1979) Ecologia do Cerrado, 1st edn. EDUSP-Ed, São Paulo, p.173. 2. Bolzani, V.S. et al. (1996). J. Braz. Chem. Soc. 7:157–160. 3. Bolzani, V.S. et al. (1997) Phytochemistry 46: 305–308.