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dc.contributor.supervisor Ata, Athar (Chemistry) en_US
dc.contributor.author Lam, Cheuk Wing
dc.date.accessioned 2012-09-28T14:22:39Z
dc.date.available 2012-09-28T14:22:39Z
dc.date.issued 2012-09-28
dc.identifier.uri http://hdl.handle.net/1993/9159
dc.description.abstract This thesis describes phytochemical studies on Buxus macowanii, a medicinal plant collected from South Africa and the fungal transformation of glycyrrhetinic acid (71), a triterpenoid found in Glycyrrhiza plants. The crude methanolic extract of B. macowanii was active in the acetylcholinesterase inhibition assay (IC50 = 30 μg/mL). Chemical investigation of its alkaline dichloromethane extract afforded five novel triterpenoidal alkaloids, 31-hydroxybuxatrienone (56), macowanioxazine (57), 16α-hydroxyma- cowanitriene (58), macowanitriene (59), and macowamine (60), along with two known Buxus bases, Nb-demethylpapillotrienine (61) and moenjodaramine (62). Compounds 56, 57, and 61 exhibited different level of AChE inhibitory activities with compound 56 being significantly active (IC50 = 8.0 μM). Glycyrrhetinic acid (71) was incubated with Curvularia lunata (ATCC 12017) for ten days to afford one metabolite which was characterized by NMR spectral data as known biotransformed product, 3-oxo-glycyrrhetinic acid (85). This metabolite was previously obtained through biotransformation of 71 by using other fungi. en_US
dc.rights info:eu-repo/semantics/openAccess
dc.subject Buxus en_US
dc.subject macowanii en_US
dc.subject AChE en_US
dc.subject Alzheimer en_US
dc.subject biotransformation en_US
dc.title Phytochemical studies on Buxus macowanii and microbial transformation of glycyrrhetinic acid en_US
dc.type info:eu-repo/semantics/masterThesis
dc.degree.discipline Chemistry en_US
dc.contributor.examiningcommittee Hultin, Philip (Chemistry) Aluko, Rotimi (Human Nutritional Sciences) en_US
dc.degree.level Master of Science (M.Sc.) en_US
dc.description.note October 2012 en_US


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