From more sustainable isocyanide-based multicomponent reactions to spiro-heterocyclic compound syntheses
- Authors: Salami, Sodeeq Aderotimi
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432229 , vital:72853 , DOI 10.21504/10962/432229
- Description: The global pharmaceutical industry has undergone profound transformations in the past two decades in the search for new drugs. For this reason, most pharmaceutical companies made significant investments not only in the development of new drugs but new methodologies. Modern drug development is confronted with the challenge of developing chemical reactions that are highly capable of providing most of the elements of structural complexity and diversity with the fewest possible synthetic steps for the specific target with the most intriguing properties. The discovery of more sustainable, environmentally friendly reactions capable of forming multiple bonds in a single step has been a challenge in organic synthesis over the years. Many organic chemists have recently started focusing on creative ways of reducing environmental pollution. The use of hazardous solvents has been reduced or eliminated in research to limit harm to both people and the environment. The pursuit of this goal has drawn many organic chemists to the study of various sustainable synthetic techniques including catalysis, aqueous organic reactions and mechanochemistry. The scope of this thesis was to apply sustainable techniques to design multicomponent synthetic protocols for the Passerini reaction and further apply these new protocols to construct spiro-heterocyclic compounds, all based on green chemistry principles. There is a need to develop rapid, efficient, and versatile strategies for the synthesis of bioactive molecules via multicomponent reactions. This project tried to avoid some of the pitfalls of traditional approaches, such as toxicity, low yield, long reaction times, harsh conditions, experimental complexity, and limited functionalization scope. This was achieved by focussing on the use of isonitriles and isothiocyanates as key reactive intermediates, and making extensive use of aqueous reaction conditions, mechanochemistry and microwave activation. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Authors: Salami, Sodeeq Aderotimi
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432229 , vital:72853 , DOI 10.21504/10962/432229
- Description: The global pharmaceutical industry has undergone profound transformations in the past two decades in the search for new drugs. For this reason, most pharmaceutical companies made significant investments not only in the development of new drugs but new methodologies. Modern drug development is confronted with the challenge of developing chemical reactions that are highly capable of providing most of the elements of structural complexity and diversity with the fewest possible synthetic steps for the specific target with the most intriguing properties. The discovery of more sustainable, environmentally friendly reactions capable of forming multiple bonds in a single step has been a challenge in organic synthesis over the years. Many organic chemists have recently started focusing on creative ways of reducing environmental pollution. The use of hazardous solvents has been reduced or eliminated in research to limit harm to both people and the environment. The pursuit of this goal has drawn many organic chemists to the study of various sustainable synthetic techniques including catalysis, aqueous organic reactions and mechanochemistry. The scope of this thesis was to apply sustainable techniques to design multicomponent synthetic protocols for the Passerini reaction and further apply these new protocols to construct spiro-heterocyclic compounds, all based on green chemistry principles. There is a need to develop rapid, efficient, and versatile strategies for the synthesis of bioactive molecules via multicomponent reactions. This project tried to avoid some of the pitfalls of traditional approaches, such as toxicity, low yield, long reaction times, harsh conditions, experimental complexity, and limited functionalization scope. This was achieved by focussing on the use of isonitriles and isothiocyanates as key reactive intermediates, and making extensive use of aqueous reaction conditions, mechanochemistry and microwave activation. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
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Phytoplankton communities provide insight into ecosystem functioning of the Agulhas Current system
- Authors: Gibb, Ross-Lynne Alida
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422646 , vital:71965
- Description: Access restricted. Embargoed until 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Authors: Gibb, Ross-Lynne Alida
- Date: 2023-03-31
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/422646 , vital:71965
- Description: Access restricted. Embargoed until 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2023
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Saul Msane: friend or foe of the people? The life of the late nineteenth to early twentieth centuries South African politician and journalist
- Authors: Mokoatsi, Thapelo
- Date: 2023-03-30
- Subjects: Saul Msane , Elite (Social sciences) , African National Congress , Politicians South Africa Biography , Political dispute , Abantu-Batho , Enemy of the people
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/409799 , vital:70631 , DOI 10.21504/10962/409802
- Description: Saul Msane was a prominent founding member of the ANC and an active journalist and editor of the ANC newspaper Abantu-Batho. His career generated controversy. Towards the end of his life, he had a feud with his colleagues in the African National Congress (henceforth Congress) that led to him being labelled isitha sabantu, “the enemy of the people” for his refusal to support the Shilling strike of 1918, an accusation which was retracted a year after his death in 1919. The label of isitha sabantu levelled against Msane, had the effect of ending his political prominence in the Transvaal, forcing him to relocate to kwaNongoma where he died shortly thereafter. Msane’s years in the Congress amounted to about seven years, between 1912, the founding of the Congress, and the demise of his career in 1919. Msane’s seven years in Congress were characterised by controversies, clashes, and conflicts owing to his perceived elitism. In Congress historiography Msane is an obscure and elusive figure, he lives here and there in a footnote, as a supporting statement or a mentioned in mere passing. His marginalisation reveals some of the gaps within the history of Congress and invites us to write about those who did not emerge from the history of Congress necessarily as heroes. This thesis sets out to write a biography of Msane and document his political career beyond that one moment in which he came to be “isitha sabantu”. While Msane’s Congress career was comparably short and filled with tensions, an archive of his life exists. This study is an exploration of that archive to reconstruct the biography of a once prominent leader who dies in political exile from the Congress movement. This thesis sets out to do two key things in relation to reconstructing Msane’s life: Firstly, it reconstructs the longer biography of Msane’s political life by drawing on the existing archives, and thus filling in the South African historical record in that regard. Secondly, at the broader conceptual and historiographical level, it argues that the controversies surrounding Msane’s persona and character illustrate that conceptions of elitism and the nature of being ‘elite’ were key to the politics of Congress at the time. , U-Saul Msane wayengomunye wabasunguli beqembu lika-African National Congress (uKhongolose) futhi eyIntatheli nomhleli wephephandaba i-Abantu-Batho. Umsebenzi ayewenza waba nezingqinamba eziningi ngokwezepolitiki. Ngasekugcineni kwempilo yakhe waba nokungazwani nabaholi ayesebenza nabo kuKhongolose okwadala ukuba abizwe ngesitha sabantu ngenxa yokuba engavumelananga nesiteleka sango-1918 lapho abasebenzi babelwela ukukhushulelwa amaholo. Leligama lokubizwa ngesitha sabantu lahoxiswa ngo 1919 sekudlule unyaka engasekho emhlabeni. Lokubizwa ngesitha sabantu kwalilimaza igama lakhe kwezepolitiki e-Transvaal waze wathutha wayohlala kwaNongoma nokuyilapho ashonela khona. Iminyaka uMsane ayisebenzele uKhongolose yaba isikhombisa, kusukela ekusungulweni kwayo ngo 1912 kuze kufike ekulimaleni komsebenzi wakhe wezepolitiki ngo 1919. Kuleminyaka eyisikhombisa umsebenzi wakhe kuKhongolose wawubhekene nokugxekwa okukhulu nokubukeka njengomuntu onokuzenza ngcono kunabanye abantu. Emlandweni kaKhongolose uMsane akavezwa ngendlela emfanele, kukhulunywa ngaye kudlulwa nje. Lokunganakwa kukaMsane emlandweni kaKhongolose kusiphoqa ukuba sibhale ngabaholi abangaqakanjiswa. Lolucwaningo luveza umlando kaMsane ngokujulile ngaphezu kwangalesikhathi abizwa khona ngesitha sabantu. Noma umsebenzi kaMsane kuKhongolose wabamfushane kunabanye futhi ugcwele izinto kodwa noko ingobo yawo ikhona. Lolucwaningo lucubungula lengobo ukuhlaziya nokubhala kabusha umlando wengqalabutho eyagcina ishonela ngaphandle kombutho kaKhongolose. Loluphando lifisa ukwenza izinto ezimbili: Okokuqala, ibhala kabusha umlando omude wezepolitiki kaMsane kusetshenziswa ulwazi olukhona. Loku kuzosiza ukunothisa umlando wezepolitiki wezwe laseNingizimu Afrika. Okwesibili, ezingeni lobunzululwazi, lolucwaningo luveza ukuthi izinkinga uMsane ahlangabezana nazo zazisukele endleleni okwakubukwa ngayo indaba yokucwasana ngazinga empilo abantu, kwakuyinto ejulile kuKhongolose ukubukeka kwabanye sengathi bazenza ngcono. , Thesis (PhD) -- Faculty of Humanities, History, 2023
- Full Text:
- Authors: Mokoatsi, Thapelo
- Date: 2023-03-30
- Subjects: Saul Msane , Elite (Social sciences) , African National Congress , Politicians South Africa Biography , Political dispute , Abantu-Batho , Enemy of the people
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/409799 , vital:70631 , DOI 10.21504/10962/409802
- Description: Saul Msane was a prominent founding member of the ANC and an active journalist and editor of the ANC newspaper Abantu-Batho. His career generated controversy. Towards the end of his life, he had a feud with his colleagues in the African National Congress (henceforth Congress) that led to him being labelled isitha sabantu, “the enemy of the people” for his refusal to support the Shilling strike of 1918, an accusation which was retracted a year after his death in 1919. The label of isitha sabantu levelled against Msane, had the effect of ending his political prominence in the Transvaal, forcing him to relocate to kwaNongoma where he died shortly thereafter. Msane’s years in the Congress amounted to about seven years, between 1912, the founding of the Congress, and the demise of his career in 1919. Msane’s seven years in Congress were characterised by controversies, clashes, and conflicts owing to his perceived elitism. In Congress historiography Msane is an obscure and elusive figure, he lives here and there in a footnote, as a supporting statement or a mentioned in mere passing. His marginalisation reveals some of the gaps within the history of Congress and invites us to write about those who did not emerge from the history of Congress necessarily as heroes. This thesis sets out to write a biography of Msane and document his political career beyond that one moment in which he came to be “isitha sabantu”. While Msane’s Congress career was comparably short and filled with tensions, an archive of his life exists. This study is an exploration of that archive to reconstruct the biography of a once prominent leader who dies in political exile from the Congress movement. This thesis sets out to do two key things in relation to reconstructing Msane’s life: Firstly, it reconstructs the longer biography of Msane’s political life by drawing on the existing archives, and thus filling in the South African historical record in that regard. Secondly, at the broader conceptual and historiographical level, it argues that the controversies surrounding Msane’s persona and character illustrate that conceptions of elitism and the nature of being ‘elite’ were key to the politics of Congress at the time. , U-Saul Msane wayengomunye wabasunguli beqembu lika-African National Congress (uKhongolose) futhi eyIntatheli nomhleli wephephandaba i-Abantu-Batho. Umsebenzi ayewenza waba nezingqinamba eziningi ngokwezepolitiki. Ngasekugcineni kwempilo yakhe waba nokungazwani nabaholi ayesebenza nabo kuKhongolose okwadala ukuba abizwe ngesitha sabantu ngenxa yokuba engavumelananga nesiteleka sango-1918 lapho abasebenzi babelwela ukukhushulelwa amaholo. Leligama lokubizwa ngesitha sabantu lahoxiswa ngo 1919 sekudlule unyaka engasekho emhlabeni. Lokubizwa ngesitha sabantu kwalilimaza igama lakhe kwezepolitiki e-Transvaal waze wathutha wayohlala kwaNongoma nokuyilapho ashonela khona. Iminyaka uMsane ayisebenzele uKhongolose yaba isikhombisa, kusukela ekusungulweni kwayo ngo 1912 kuze kufike ekulimaleni komsebenzi wakhe wezepolitiki ngo 1919. Kuleminyaka eyisikhombisa umsebenzi wakhe kuKhongolose wawubhekene nokugxekwa okukhulu nokubukeka njengomuntu onokuzenza ngcono kunabanye abantu. Emlandweni kaKhongolose uMsane akavezwa ngendlela emfanele, kukhulunywa ngaye kudlulwa nje. Lokunganakwa kukaMsane emlandweni kaKhongolose kusiphoqa ukuba sibhale ngabaholi abangaqakanjiswa. Lolucwaningo luveza umlando kaMsane ngokujulile ngaphezu kwangalesikhathi abizwa khona ngesitha sabantu. Noma umsebenzi kaMsane kuKhongolose wabamfushane kunabanye futhi ugcwele izinto kodwa noko ingobo yawo ikhona. Lolucwaningo lucubungula lengobo ukuhlaziya nokubhala kabusha umlando wengqalabutho eyagcina ishonela ngaphandle kombutho kaKhongolose. Loluphando lifisa ukwenza izinto ezimbili: Okokuqala, ibhala kabusha umlando omude wezepolitiki kaMsane kusetshenziswa ulwazi olukhona. Loku kuzosiza ukunothisa umlando wezepolitiki wezwe laseNingizimu Afrika. Okwesibili, ezingeni lobunzululwazi, lolucwaningo luveza ukuthi izinkinga uMsane ahlangabezana nazo zazisukele endleleni okwakubukwa ngayo indaba yokucwasana ngazinga empilo abantu, kwakuyinto ejulile kuKhongolose ukubukeka kwabanye sengathi bazenza ngcono. , Thesis (PhD) -- Faculty of Humanities, History, 2023
- Full Text:
Bioinformatics tool and web server development focusing on structural bioinformatics applications
- Authors: Nabatanzi, Margaret
- Date: 2022-10-14
- Subjects: Structural bioinformatics , Proteins Structure , Protein structure prediction , Proteins Conformation , Protein complex
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365700 , vital:65777 , DOI https://doi.org/10.21504/10962/365700
- Description: This thesis is divided into two main sections: Part 1 describes the design, and evaluation of the accuracy of a new web server – PRotein Interactive MOdeling (PRIMO-Complexes) for modeling protein complexes and biological assemblies. The second part describes the development of bioinformatics tools to predict HIV-1 drug resistance and support bioinformatics research and education. Recent technological advances have resulted in a tremendous increase in the number of sequences and protein structures deposited in the Universal Protein Resource Knowledgebase (UniProtKB) and the Protein Data Bank (PDB). However, the number of sequences has increased at a higher rate compared with the experimentally solved multimeric protein structures. This is partly due to advances in high-throughput sequencing technology. To fill this protein sequence-structure gap, computational approaches have been developed to predict protein structures from available sequences. Computational approaches include template-based and ab initio modeling with the former being the most reliable. Template-based modeling process can be achieved using either standalone software or automated modeling web servers. However, using standalone software requires familiarity with command-line interfaces as well as utilising other intermediate programs which could be daunting to novice users. To alleviate some of these problems, the modeling process has been automated, however, it still has numerous challenges. To date, only a few web servers that support multimeric protein modeling have been developed and even these provide little, if any user involvement in the process. To address some of these issues, a new web server – PRIMO-Complexes – was developed to model protein complexes and biological assemblies. The existing PRIMO web server could only model monomeric proteins. Part 1 of this thesis provides a detailed account of the development and evaluation of PRIMO-Complexes. The rationale for developing this new web server was based on the understanding that most proteins function as protein multimers and often the ligand-binding sites, and enzyme active sites are located at the protein-protein interfaces. It, therefore, necessitated developing capabilities for modeling multimeric proteins. PRIMO-Complexes web server was developed using the Waterfall system development life cycle model, is based on the Django web framework and makes use of high-performance computing resources to execute jobs. The accuracy of the algorithms embedded in PRIMO- Complexes was evaluated and the results were promising. Additionally, PRIMO-Complexes performs comparatively well in relation to other web servers that offer multimeric protein modeling. Another unique feature of PRIMO-Complexes is its interactivity. The webserver was developed with capabilities for allowing users to model multimeric proteins with an appreciable degree of control over the process. In the second part of the thesis several other bioinformatics tools are described, for example, a webserver for predicting HIV-1 drug resistance, the RUBi protein model repository, and a bioinformatics web portal for education and research resources. RUBi protein model repository stores verified theoretical models built using various modeling approaches. This enables users to easily access models to reproduce and/or further the research. This is described in chapter 5. Chapter 6 describes the design and development of the Human Immunodeficiency type 1 Resistance Predictor (HIV-1 ResPredictor), a web application that employs artificial neural networks (ANN) to predict drug resistance in patients infected with HIV-1 subtype B. The ANNs and subtype classifiers performed well making this web application potentially useful to both clinicians and researchers in this era of personalised medicine. Finally, chapter 7 describes a bioinformatics education web portal that equips students with information on how to use bioinformatics online resources. Being aware of these resources is not enough without a deeper understanding and guidance on how to apply bioinformatics methods to solve practical problems. This web portal was aimed at familiarising students with the basic terminology and approaches in structural bioinformatics. Students will potentially gain skills to conduct real-life bioinformatics research to obtain biological insights. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Authors: Nabatanzi, Margaret
- Date: 2022-10-14
- Subjects: Structural bioinformatics , Proteins Structure , Protein structure prediction , Proteins Conformation , Protein complex
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365700 , vital:65777 , DOI https://doi.org/10.21504/10962/365700
- Description: This thesis is divided into two main sections: Part 1 describes the design, and evaluation of the accuracy of a new web server – PRotein Interactive MOdeling (PRIMO-Complexes) for modeling protein complexes and biological assemblies. The second part describes the development of bioinformatics tools to predict HIV-1 drug resistance and support bioinformatics research and education. Recent technological advances have resulted in a tremendous increase in the number of sequences and protein structures deposited in the Universal Protein Resource Knowledgebase (UniProtKB) and the Protein Data Bank (PDB). However, the number of sequences has increased at a higher rate compared with the experimentally solved multimeric protein structures. This is partly due to advances in high-throughput sequencing technology. To fill this protein sequence-structure gap, computational approaches have been developed to predict protein structures from available sequences. Computational approaches include template-based and ab initio modeling with the former being the most reliable. Template-based modeling process can be achieved using either standalone software or automated modeling web servers. However, using standalone software requires familiarity with command-line interfaces as well as utilising other intermediate programs which could be daunting to novice users. To alleviate some of these problems, the modeling process has been automated, however, it still has numerous challenges. To date, only a few web servers that support multimeric protein modeling have been developed and even these provide little, if any user involvement in the process. To address some of these issues, a new web server – PRIMO-Complexes – was developed to model protein complexes and biological assemblies. The existing PRIMO web server could only model monomeric proteins. Part 1 of this thesis provides a detailed account of the development and evaluation of PRIMO-Complexes. The rationale for developing this new web server was based on the understanding that most proteins function as protein multimers and often the ligand-binding sites, and enzyme active sites are located at the protein-protein interfaces. It, therefore, necessitated developing capabilities for modeling multimeric proteins. PRIMO-Complexes web server was developed using the Waterfall system development life cycle model, is based on the Django web framework and makes use of high-performance computing resources to execute jobs. The accuracy of the algorithms embedded in PRIMO- Complexes was evaluated and the results were promising. Additionally, PRIMO-Complexes performs comparatively well in relation to other web servers that offer multimeric protein modeling. Another unique feature of PRIMO-Complexes is its interactivity. The webserver was developed with capabilities for allowing users to model multimeric proteins with an appreciable degree of control over the process. In the second part of the thesis several other bioinformatics tools are described, for example, a webserver for predicting HIV-1 drug resistance, the RUBi protein model repository, and a bioinformatics web portal for education and research resources. RUBi protein model repository stores verified theoretical models built using various modeling approaches. This enables users to easily access models to reproduce and/or further the research. This is described in chapter 5. Chapter 6 describes the design and development of the Human Immunodeficiency type 1 Resistance Predictor (HIV-1 ResPredictor), a web application that employs artificial neural networks (ANN) to predict drug resistance in patients infected with HIV-1 subtype B. The ANNs and subtype classifiers performed well making this web application potentially useful to both clinicians and researchers in this era of personalised medicine. Finally, chapter 7 describes a bioinformatics education web portal that equips students with information on how to use bioinformatics online resources. Being aware of these resources is not enough without a deeper understanding and guidance on how to apply bioinformatics methods to solve practical problems. This web portal was aimed at familiarising students with the basic terminology and approaches in structural bioinformatics. Students will potentially gain skills to conduct real-life bioinformatics research to obtain biological insights. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
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Identification and characterisation of microbial communities and their metabolic potential in meltwater ponds, Western Dronning Mau Land, Antarctica
- Authors: Van Aswegen, Sunet
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365723 , vital:65779
- Description: Thesis embargoed. Expected release date early 2024. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Authors: Van Aswegen, Sunet
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365723 , vital:65779
- Description: Thesis embargoed. Expected release date early 2024. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
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