Browsing by Author "Yalo, Masande Nicholas"

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    An investigation of the natural products composition of Porphyra capensis (a red seaweed)
    (University of the Western Cape, 2017) Yalo, Masande Nicholas; Mabusela, Wilfred T.
    Plants have been widely used in traditional medicine for a number of ailments, among which may be included infectious diseases such as colds, influenza, chicken pox, TB, etc. as well as lifestyle diseases such as diabetes and cancer. Seaweeds have also been shown to contribute to the maintenance of health through their nutritional and medicinal properties and recently, a great deal of interest has developed towards the isolation of bioactive compounds from marine sources due to their numerous health benefits. Furthermore, marine algae are valuable sources of structurally diverse metabolites with scientifically proven therapeutic claims. Chemical constituents of red seaweed, Porphyra capensis was investigated in this present study along with subsequent brine shrimp lethality assay analysis of the crude extracts. The compounds isolated from the plant were from the hexane (6) and butanol (2) extracts. These compounds were all isolated and purified by various chromatographic techniques, namely silica gel chromatography, Sephadex LH-20 gel as well as C18 reversed phase silica gel. The structures of the isolated compounds were analysed and characterised by NMR, GC-MS, ESI MS and FTIR spectroscopy. Eight compounds were isolated and identified as phytol, desmosterol, 9-eicosenoic acid, 5,8,11,14,17-eicosapentanoic acid, palmitic acid, methyl (E)-hexadec-9-enoate, glycerol and compound 1 (novel compound). All the compounds were isolated from Porphyra capensis for the first time. The hexane, butanol and methanol extracts were found to be non-toxic with the brine shrimp test LC50 value at least two times greater than ?g/ml.
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    Phytochemical studies on extracts of selected South African indigenous medicinal plants
    (University of the Western Cape, 2022) Yalo, Masande Nicholas; Mabusela, Wilfred T.
    Nature has been identified as a rich source of potentially useful chemicals. Throughout the years, phytochemical studies have led to the unearthing of a huge number of natural products, their chemical diversity is unique and many of them possess various biological activities. South Africa is blessed with a rich plant biodiversity of +24,000 indigenous plants, representing about 10% of all higher plants on earth and with more than 50 % of such plant species found nowhere else in the world but in South Africa. However, only a few of the South African medicinal plants have been exploited to their full potential. Screening of more medicinal plants for biological activities and phytochemicals is important for finding potential new compounds for therapeutic uses.