Abstract
Phytochemical investigation of the flowering aerial parts of Echinops galalensis (Asteraceae) led to the isolation of a new taraxasteryl triterpene, 3 beta-acetoxy-taraxast-12, 20(30)-diene-11 alpha-21 alpha-diol (1), together with nine known metabolites, alpha-amyrin (2), beta-sitosterol (3), erythrodiol (4), lup-20(29)-ene-1,3-diol (5), 1,5-dicaffeoylquinic acid (6), 3,5-dicaffeoylquinic acid (7), 3,4-dicaffeoylquinic acid (8), 4,5-dicaffeoylquinic acid (9) and apigenin-7-O-beta-D-glucoside (10). The structure of the new compound was determined by comprehensive analyses of their 1D and 2D NMR, mass spectral (HR-EI) data and comparison with previously known analogs. The effect of the methanol extract of E. galalensis, its fractions as well as compounds (1-10) on human hepatoma cell line (Huh7) was evaluated according to aspartate aminotransferase (AST), alanine transaminase (ALT), superoxide dismutase (SOD) activities and malondialdehyde (MDA) level before and after exposure of the cells to carbon tetrachloride (CCl4). It was found that pre-treatment of human hepatoma cell line (Huh7) with the tested samples (100 mu g/ml) prior to CCl4 challenge protected against cell injury. The protective effect of E. galalensis was suggested to be mediated, at least partly, by its antioxidant activity. (C) 2012 Phytochemical Society of Europe. Published by Elsevier B. V. All rights reserved.