Uteroactive constituents from Combretum kraussii

We have established that certain extracts of Combretum kraussii Hochst root s cause contractions in isolated rat uterine tissue, and have purified the most active uterotonic components. The mode of action of the various extrac ts/components on isolated rat uterus falls into three different categories. The activity of crude extracts from leaves and branches of C.erythrophyllu m (Burch.) Send. and C. kraussii Hochst was also measured. We have identifi ed the following compounds from root extracts: combretastatin, combretastat in A-1 and combretastatin B-1 as well as the corresponding 2-O-beta-D-gluco sides of the latter two combretastatins, beta-sitosterol, ellagic acid and the di- and trimethyl ethers of ellagic acid. This is the first report of t he occurrence of combretastatin and ellagic acid derivatives in this Combre tum species.