The process of investigating plants to identify chemical substances is of great interest to natural product scientists because there is a need to discover new drugs for treating diseases. In our study, plant extracts were prepared from the bulbs of Crinum macowanii, Boophane disticha as well as Eucomis autumnalis and further experiments were made on the extracts. High performance liquid chromatography with other instruments (ultra-violet detector, mass spectrometer) coupled to it, were used in the search for the active ingredients in the extracts prepared. Old methods of separation and identification such as flash column chromatography and thin layer chromatography also played an important role in the investigation of these extracts. Other techniques such as nuclear magnetic resonance (NMR), helped in the structural elucidation once the compounds had been purified. The use of analytical techniques (HPLC-MS, NMR) was found to be important in the process of investigating the extracts and the presence of various active ingredients was confirmed. The methods used traditionally for extract preparation (boiling plants in water for certain amount of time) were investigated and the important relationship between the boiling time and concentration of the active components was established. It was found that the increase in boiling time of the plants during preparation decreases the concentrations of the active components. The experiments conducted provide some scientific evidence which motivates that the traditional preparations of the plants are related to the dosage.
Dissertation (MSc (Chemistry))--University of Pretoria, 2008.