Constituents of Croton menthodorus and their effects on electrically induced contractions of the guinea-pig isolated ileum

The present study examines the effects of the extracts [petroleum ether, CH Cl3 CHCl3MeOH (9:1) and MeOH], partially purified fractions and pure compou nds from Croton menthodorus on the electrically induced contractions of the isolated guinea-pig ileum (ECI). The results of the experiments indicate that CHCl3/MeOH (9:1) and MeOH extr acts, tested at concentrations of 100, 50 and 25 mu g/mL, dose-dependently reduced the guinea-pig ileum contractions, whereas petroleum ether and CHCl 3 extracts did not affect it. Furthermore, the partially purified fractions III-VI from the CHCl3/MeOH extract, each tested at concentrations of 100, 50 and 25 mu g/mL also inhibited ECI, Finally, pure compound 1 (6 x 10(-6), 3 x 10(-6), 1 x 10(-6) M) isolated and purified from the most active fract ion III significantly reduced, in a dose-dependent manner, the electrical c ontractions of the ileum. Compound 1 was identified by NMR and EI-MS data as the morphinandien-7-one, O-methylflavinantine. Copyright (C) 2000 John Wiley & Sons, Ltd.