Pelargonium sidoides and P. reniforme are indigenous to South Africa with the centre of diversity in the Eastern Cape Province. The two species are highly valued in South Africa by traditional healers. For hundreds of years various ethnic groups have used root extracts of P. sidoides as a remedy for coughs, upper respiratory tract irritations and gastrointestinal conditions. An ethanolic extract is used in the proprietary herbal tincture known as Umkaloabo® that is currently successfully marketed in Germany with sales that have escalated over 700%. Despite the commercial interest in P. sidoides and P. reniforme very few studies have been conducted to document the full phytochemical range of variation for natural populations. This project will determine the total phenolic content and phytochemical variation between and within natural populations of P. sidoides and P. reniforme. Phytochemical profiles of P. sidoides and P. reniforme will be constructed and compared. A simple and refined procedure for the validation of raw materials will be proposed. Plant samples will be collected from different localities in the Eastern Cape Province South Africa. Water and Methanol dichloromethane (1:1) extracts of the roots and shoots will be analysed respectively to determine its phytoconstituents by means of total phenolic content, near infrared spectroscopy (NIR) followed by high performance liquid chromatography (HPLC) and thin layer chromatography (TLC). The data obtained from NIRS and HPLC will be used to detect the relationships amongst all samples and variables hence all the data must be processed simultaneously. Phytochemical fingerprints of the two species will be compared to determine variation between the two taxa.
Principal supervisor: Prof AM Viljoen
Co-supervisor: Dr M Manley (Stellenbosch)