ABSTRACT In recent years, there has been an increase in fatal road accidents in Namibia claiming many lives each year. Traffic accidents are often related to the use of alcohol, illegal drugs or psychoactive medicines. A rapid low volume dispersive liquid-liquid microextraction (DLLME) method in combination with gas chromatography-mass spectrometry (GC-MS) detection was developed for the simultaneous determination of illicit psychoactive drugs in blood (those used most commonly in Namibia: c...
Abstract Metal nanoparticles are endowed with optical, electrical physical and chemical properties and have become attractive materials for commercialization applications in optical spectroscopies, electrical devices and catalytic applications. Among them, silver nanoparticles (Ag-NPs) have distinctive physico-chemical and biological properties such as antimicrobial, chemical stability and catalytic properties. Namibia, a semi-arid country, relies on man-made dams to obtain water for potable...
ABSTRACT Tephrosia lupinifolia is used traditionally for the treatment of malaria, diarrhea, toothache and tuberculosis. Two flavonoids, lupinifolin and lupinifolinol were previously isolated from the hexane root extract of T. lupinifolia, but there are no reports on phytochemical and pharmacological studies conducted on the stems and leaves of the plant. The purpose of this study was to prepare and fractionate crude extracts from the leaves and stems of T. lupinifolia, and to evaluate their...
ABSTRACT Marine-derived endophytic fungi isolated from mangrove plants are an important and novel resource of natural bioactive compounds with their potential applications in medicine, agriculture and food industry. There are many instances that seem to suggest that, some of the novel metabolites previously isolated from certain species of marine plants and invertebrates are actually metabolites of marine-derived endophytic fungi. In this project, chemical screening of mangrove plantsConocarp...
ABSTRACT There is an ever-growing interest in the Paenibacillus genus as a result of reports that strains belonging to this genus have several important properties. These properties include promotion of plant growth, bioremediation and the biosynthesis of structurally intriguing molecules with unrivalled biological activities and mechanisms of action. However, the agricultural applications of the aforementioned molecules far outweigh their use in medicine. In this current report, a novel Paen...
ABSTRACT Non-ribosomal peptides (NRPs) are currently receiving considerable interests for possible development as effective alternatives to clinically failing conventional small molecule antibiotics. Particularly, NRPs produced by the genus Streptomyces have attracted considerable attention given the antibiotic production history of the genus. In this current report, a novel Ghanaian Streptomyces sp. strain DE2E isolated from the high biodiversity rich wetlands of the Brong-Ahafo Region of Gh...
Abstract Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), is one of the leading causes of death globally, especially in low and middle-income countries. TB is primarily a curable disease, with chemotherapy predicated on a combination of four drugs. The increase in multiple forms of drugresistant TB is a major cause for concern, underpinning the importance of a continuous pipeline of new anti-TB agents. Drug repositioning – that is, the optimization of existing drugs for new th...
ABSTRACT There is an urgent need for new antimalarials following the emergence of Plasmodium falciparum strains with reduced sensitivity to the currently used artemisinin combination therapies. Classical aminoquinoline-based drugs inhibit the formation of haemozoin (HZ) thereby causing parasite death from the cellular accumulation of toxic ‘free’ haem. Coincidentally, this immutable pathway also exists in Schistosoma mansoni, and presents a vulnerable target for drug design in these haema...
ABSTRACT This investigation examined petroleum ether, acetone/chloroform, and ethanol extracts of the whole stem of Dichapetalum madagascariense Poir. The petroleum ether extract afforded epifriedelanol (friedelan-3β-ol) together with two mixtures- friedelan-3-one and friedelan-3β-ol; and β-sitosterol and stigmasterol. The acetone/chloroform extract (obtained by combining the acetone and chloroform extracts) afforded friedelin (friedelan-3-one) and β-sitosterol but showed dichapetalin A o...
ABSTRACT A new liquid scintillation counting technique to resolve mixtures of two pure beta-emitting radionuclides Winifred Margaret van Wyngaardt Submitted November 2007 Methods currently available for the accurate activity resolution of dual-label solutions of pure β-emitting radionuclides are mostly time consuming and involve much effort. The goal of this thesis was therefore to devise a simpler method to achieve the same objective. The technique developed is based on elements of two liqu...
ABSTRACT The synthesis, characterization, spectroscopic and biological evaluation of 2-benzoylpyridine-s-methyldithiocarbazate (HL1 ) and di-2-pyradylketone-s-methyldithiocarbazate (HL2 ) with selected metal ions of copper (II), zinc (II), cadmium (II), nickel (II), iron (II) and cobalt (II). The ligands, HL1 and HL2 were synthesized by an acid catalyzed condensation reaction of s-methyldithiocarbazate with 2-benzoylpyradine and di-2-pyradylketone respectively. The reaction of metal salts wi...
ABSTRACT Mining is a major contributor to water pollution, which can lead to accumulation of heavy metals in aquatic systems. Mining activities in the Karstveld, specifically in the Tsumeb-Grootfontein-Otavi area, may potentially result in heavy metal pollution of water sources. A seasonal study was conducted to assess the concentration of heavy metals in aquatic systems that receive water from the Karstveld aquifer. The potential of locally occurring fish and crab species as bio-indicators ...
ABSTRACT Ozone (O3) is an allotrope of oxygen occurring naturally in the earth’s atmosphere. Its importance in environmental issues is well documented and cannot be overemphasized. Ozone reacts with carbon-carbon multiple bonds such as in alkenes via the ozonolysis process. The first step of ozonolysis involves the formation of an important but very unstable primary ozonide (POZ) which after formation, immediately rearranges to the more stable secondary ozonide (SOZ). Due to its instabilit...
ABSTRACT In order to investigate the interaction mechanism between Cadmium selenide (CdSe) quantum dots (QDs) and Moringa oleifera seeds coagulant protein (MOCP), CdSe QDs with hexagonal phase and crystalline size of 3.1-8.1 nm were synthesized in presence of organic solvent Trioctyl-n-phosphine oxide (TOPO) and Trioctyl phosphene (TOP) using colloidal synthesis. The purified mesoporous M. oleifera seeds coagulant protein (MOCP) with a surface area of 8.4134 m2 /g, was extracted from M. olei...
ABSTRACT Commiphora wildii (Omumbiri), a member of the Burseraceae family, is the most important resin‒producing plant used by Himba women for perfume. The Opuwo Processing Facility (OPF) is currently producing Omumbiri essential oil which they supply to companies in Namibia, South Africa, Germany and France. However, most of their products are sold in Southern Africa, and supply outweighs the demand. OPF is currently working on improving the reproducibility of production of the oil to mak...