Single and hybrid antimalarials based on artemisinin, chloroquine and ß-lactams : synthesis, antiplasmodial activity, cytotoxicity and effect of selected artemisinin-chloroquine hybrids on the parasitic endocytosis pathway

dc.contributor.advisorChibale, Kellyen_ZA
dc.contributor.advisorHoppe, Heinrich Cen_ZA
dc.contributor.authorFeng, Tzu-Sheanen_ZA
dc.date.accessioned2014-08-13T14:26:14Z
dc.date.available2014-08-13T14:26:14Z
dc.date.issued2009en_ZA
dc.descriptionIncludes abstract.en_ZA
dc.descriptionIncludes bibliographical references.en_ZA
dc.description.abstractMalaria remains to be one of the leading causes of morbidity and mortality throughout recorded history. It is caused by protozoan parasites of the genus Plasmodium, where P. falciparum is the most lethal. Current estimates are that over 500 million people are afflicted, while 3 million people die annually. With the emergence of resistance to antimalarial drugs in the malaria parasite, it is critical to develop new chemotherapeutic agents that can combat the disease and/or overcome resistance. This may be achieved by identifying molecules that target or interfere with unique parasitic pathways such as haemoglobin degradation or parasitic endocytosis. This thesis describes the design and synthesis of novel antimalarial agents based on the ‘Designed Multiple Ligand’ approach. Compounds were synthesized via conjugate addition or multi-component condensation reaction. 4-Aminoquinolines were hybridized with artemisinin or 1,4-naphthoquinone derivatives; selected hybrids were further investigated for their effect on the parasitic endocytosis pathway and compared to the effect of chloroquine and artemisinin on the same pathway. The effects of drug treatment on the morphology and haemoglobin levels in the parasites as well as localization of transport vesicles via immunofluorescence microscopy were determined. A series of β-lactam derivatives containing a terminal acetylene moiety were synthesized via the Staudinger and Ugi 3-component 4-centre condensation reactions. The compound with the best activity from the series was used to couple these reactions to post-condensation chemical modifications via the Mannich reaction, another multi-component reaction, to create a more diversified library. A small series of 4-aminoquinoline analogues, including amodiaquine-like compounds and bisquinoline derivatives, was also prepared in an attempt to elucidate their structure-activity relationships. The antiplasmodial and cytotoxic activities were determined for all compounds; where applicable, assays on β-haematin inhibitory activity were also carried out.en_ZA
dc.identifier.apacitationFeng, T. (2009). <i>Single and hybrid antimalarials based on artemisinin, chloroquine and ß-lactams : synthesis, antiplasmodial activity, cytotoxicity and effect of selected artemisinin-chloroquine hybrids on the parasitic endocytosis pathway</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Chemistry. Retrieved from http://hdl.handle.net/11427/6305en_ZA
dc.identifier.chicagocitationFeng, Tzu-Shean. <i>"Single and hybrid antimalarials based on artemisinin, chloroquine and ß-lactams : synthesis, antiplasmodial activity, cytotoxicity and effect of selected artemisinin-chloroquine hybrids on the parasitic endocytosis pathway."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Chemistry, 2009. http://hdl.handle.net/11427/6305en_ZA
dc.identifier.citationFeng, T. 2009. Single and hybrid antimalarials based on artemisinin, chloroquine and ß-lactams : synthesis, antiplasmodial activity, cytotoxicity and effect of selected artemisinin-chloroquine hybrids on the parasitic endocytosis pathway. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Feng, Tzu-Shean AB - Malaria remains to be one of the leading causes of morbidity and mortality throughout recorded history. It is caused by protozoan parasites of the genus Plasmodium, where P. falciparum is the most lethal. Current estimates are that over 500 million people are afflicted, while 3 million people die annually. With the emergence of resistance to antimalarial drugs in the malaria parasite, it is critical to develop new chemotherapeutic agents that can combat the disease and/or overcome resistance. This may be achieved by identifying molecules that target or interfere with unique parasitic pathways such as haemoglobin degradation or parasitic endocytosis. This thesis describes the design and synthesis of novel antimalarial agents based on the ‘Designed Multiple Ligand’ approach. Compounds were synthesized via conjugate addition or multi-component condensation reaction. 4-Aminoquinolines were hybridized with artemisinin or 1,4-naphthoquinone derivatives; selected hybrids were further investigated for their effect on the parasitic endocytosis pathway and compared to the effect of chloroquine and artemisinin on the same pathway. The effects of drug treatment on the morphology and haemoglobin levels in the parasites as well as localization of transport vesicles via immunofluorescence microscopy were determined. A series of β-lactam derivatives containing a terminal acetylene moiety were synthesized via the Staudinger and Ugi 3-component 4-centre condensation reactions. The compound with the best activity from the series was used to couple these reactions to post-condensation chemical modifications via the Mannich reaction, another multi-component reaction, to create a more diversified library. A small series of 4-aminoquinoline analogues, including amodiaquine-like compounds and bisquinoline derivatives, was also prepared in an attempt to elucidate their structure-activity relationships. The antiplasmodial and cytotoxic activities were determined for all compounds; where applicable, assays on β-haematin inhibitory activity were also carried out. DA - 2009 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2009 T1 - Single and hybrid antimalarials based on artemisinin, chloroquine and ß-lactams : synthesis, antiplasmodial activity, cytotoxicity and effect of selected artemisinin-chloroquine hybrids on the parasitic endocytosis pathway TI - Single and hybrid antimalarials based on artemisinin, chloroquine and ß-lactams : synthesis, antiplasmodial activity, cytotoxicity and effect of selected artemisinin-chloroquine hybrids on the parasitic endocytosis pathway UR - http://hdl.handle.net/11427/6305 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/6305
dc.identifier.vancouvercitationFeng T. Single and hybrid antimalarials based on artemisinin, chloroquine and ß-lactams : synthesis, antiplasmodial activity, cytotoxicity and effect of selected artemisinin-chloroquine hybrids on the parasitic endocytosis pathway. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Chemistry, 2009 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/6305en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Chemistryen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherChemistryen_ZA
dc.titleSingle and hybrid antimalarials based on artemisinin, chloroquine and ß-lactams : synthesis, antiplasmodial activity, cytotoxicity and effect of selected artemisinin-chloroquine hybrids on the parasitic endocytosis pathwayen_ZA
dc.typeDoctoral Thesis
dc.type.qualificationlevelDoctoral
dc.type.qualificationnamePhDen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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