Cytotoxic screening of selected Euphorbiaceae species. Cytotoxic triterpenes from Garcia parviflora

Previous bioassay guided studies of selected Mexican Euphorbiaceae species have revealed the presence of cytotoxic compounds representing diverse skeletal structures [1,2], and here we report the results of Garcia parviflora, Sapium nitidum, S. macrocarpum and S. glandulosum. The hexanic and ethyl acetate extracts of G. parviflora displayed cytotoxicity and they were fractionated with solvents of increasing polarity, isolating compounds 1-4. 1,2 Dehydro-2,3-seco-3-friedelanoic acid (2) and 1β-hydroxyfriedeline (4) are new natural products. Compounds 1 [3] and 3 [4] showed selective cytotoxic activity against U251 (glial cells) human cancer line (100% of cellular growth inhibition at 50µM), explaining the observed bioactivity of the extracts.

Acknowledgements: To CONACyT (México) and Coordinación de Estudios de Posgrado (UNAM). We also thank E. M. Martínez (Instituto de Biología, UNAM), A. Cano, M. T. Ramírez-Apan, M. I. Chávez, L. Velasco, R. A Toscano (Instituto de Química, UNAM).

References: 1. García, A., Delgado, G. (2006) Helv. Chim. Acta 89:16–29. 2. García, A. et al. (2006) Can. J. Chem. 84:1593–1602. 3. Moiteiro, C. et al. (2006)J. Agric. Food Chem. 54:3566–3571. 4. Maciel, M. A. M. et al. (1998) Phytochemistry 49:823–828.