ETD Collection

Permanent URI for this collectionhttps://wiredspace.wits.ac.za/handle/10539/104


Please note: Digitised content is made available at the best possible quality range, taking into consideration file size and the condition of the original item. These restrictions may sometimes affect the quality of the final published item. For queries regarding content of ETD collection please contact IR specialists by email : IR specialists or Tel : 011 717 4652 / 1954

Follow the link below for important information about Electronic Theses and Dissertations (ETD)

Library Guide about ETD

Browse

Filters

20081

Settings

Author: search.filters.author.Coovadia, Zubair Hoosen

Search Results

Now showing 1 - 1 of 1
  • No Thumbnail Available
    Item
    The antimicrobial properties and chemical composition of leaf extracts and essential oils of indigenous Pteronia species
    (2008-06-30T12:07:12Z) Coovadia, Zubair Hoosen
    Abstract The genus Pteronia consists of approximately 80 species which are widely distributed in southern Africa. For hundreds of years the indigenous people of southern Africa have turned to the earth in order to provide healing for their people. The genus Pteronia has been amongst the first species to be used by the San and Khoi-San people for treating infections and stomach ailments. Ten species were selected for the purpose of this report. The essential oils were isolated by using a Clevenger-type apparatus while the non-volatiles were extracted with acetone and methanol. The essential oils and extracts were assessed for antimicrobial activity. The disc diffusion assays included three Gram-negative bacteria; Escherichia coli, Yersinia enterocolitica and Klebsiella pneumoniae, three Gram-positive bacteria; Staphylococcus aureus, Bacillus subtilis and Bacillus cereus as well as one yeast; Candida albicans. Results indicated that the species were primarily active against Gram-positive organisms. The minimum inhibitory concentration of the ten most active species (essential oils and extracts) were determined using the microdilution method. The most promising activity was noted for P. fasiculata which had a MIC of 0.22 mg/ml against S. aureus, 0.39 mg/ml against B. cereus and 2.08 mg/ml against B. subtilis. The essential oils analysis by GC/MS revealed two chemotypes. In Pteronia pallens, P. empetrifolia and P. flexicaulis rare compounds, such as presilphiperfolol-7-ene, 7-α-(H)-silphiperfol-5-ene, 7-β-(H)-silphiperfol-5-ene, α-campholene aldehyde, silphiperfol-5-ene, camaroonan-7-α-ol, silphiperfol-7- β -ol, presilphiperfolan-9- α -ol and presilphiperfolan-8-ol (a major compound in Pteronia pallens) were recorded. A cluster analysis of the essential oil data indicated that individual collections of P. camphorata within a population were tightly clustered. Similarly, P. pallens sampled from three different localities were also united in the cluster analysis. These results suggest minimal within and between population variations for some of the species studied.