Phytochemical study of Markhamia lutea and Securidaca longipedunculata

Abstract

This study describes the extraction and isolation of active principles from two local plants and an investigation of their chemical constitution and anti-bacterial properties. The two plants, Markhamia lutea and Securidaca longipedunculata, are found in Uganda. Markahamia lutea is widely distributed in Uganda and other parts of East Africa, but in Uganda Securidaca longipedunculata is only found in certain localised areas. Both plants are constituents of a herbal preparation, herein referred to as Formula H, which has been used by one prominent herbalist in the alleviation of HIV/AIDS symptoms. In all the extractions of both plants, only the roots were examined because they are the parts which are used by the herbalist to make the formula. Chemical analysis of the extracts of Markhamia lutea root revealed that they contained alkaloids and saponins which appeared to contribute to the pharmacological activity. Rhamnose, a sugar, is most likely to be found in this plant. Sterol and/or terpenes were found to be present. The phytochemical screening of Securidaca longipedunculata extract showed that the components are flavone aglycones, tannins and emodols. A shrimp litharity test was carried out on all the crude extracts of both plants. The results obtained compare very well with the accepted one for crude extracts. Anti-bacterial Activity Test (AAT) was done on three types of bacteria i.e. staphylococcas aureus, Escherichia coli and pseudomonas aeruginosa. It was found that the components of petroleum extract of Markhamia lutea showed the highest degree of activity towards the test organisms. Only one isolated component of the ethanol extract of Markhamia lutea showed considerable activity and only to one of the test organisms (Escherichia coli). Each isolated component of Securidaca longipedunculata showed activity towards at least one of the test organisms. An attempt to determine the structure of the different compounds using spectroscopic analysis was carried out but full interpretation of the data could not be achieved.