Ph.D. (Chemistry) / Alchornea species (Euphorbiaceae) have been used in traditional medicine across Africa and are well known to display broad spectrum biological activities including anti‐microbial, antiinflammatory and anti‐cancer activities. This project is aimed at discovering bioactive compounds for anti‐microbial and anti‐cancer therapy from plants of the Alchornea species and developing suitable nanocarrier drug delivery systems (DDS) as drug or compound transporters using gold nanoparticles and natural polymers. The plant material (roots, stems and leaves) was collected in bulk from an uncultivated farmland of the Elounden Mount, in the Yaoundé central region of Cameroon. The extracts were prepared using solvents of varying polarity in order to extract a wide range of phytochemicals. The extracts of A. cordifolia, A. floribunda and A. laxiflora as well as those isolated compounds that were sufficiently pure, were screened for antibacterial activity against four Gram‐positive bacteria (Bacillus cereus, Enterococcus faecalis, Staphylococcus aureus and S. saprophyticus) and four Gram‐negative bacteria (Escherichia coli, Klebsiella pneumonia, Moraxella catarrhalis and Proteus mirabilis), as well as antimycobacterial activity (Mycobacterium aurum and M. smegmatis). The anti‐cancer properties were similarly tested against SNO oesophageal cancer, breast cancer (MDA‐MB‐231 and MCF‐7), and leukemia HL‐60 cell lines. The antimicrobial activities were evaluated using the micro‐dilution assay while the anticancer activity was evaluated by means of cell viability (MTT assay, Alamar blue, trypan blue and an ATP assays). The isolation of compounds and synthesis of derivatives were performed by exhaustive chromatographic techniques and suitable organic reactions. The structures of the compounds were determined by means of spectroscopic methods (FT‐IR, MS, 1D and 2D NMR). Three compounds (AC3.1, AC2.4 and 3HB) were used to synthesize DDS and were characterized using UV‐Vis, FT‐IR, TEM, SEM, XRD, EDS, DLS and zeta potential.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:12754 |
| Date | 04 November 2014 |
| Creators | Siwe Noundou, Xavier |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
| Rights | University of Johannesburg |
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