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Characterisation, synthesis and antimycobacterial activity of naphthoquinones isolated from Euclea natalensis
Dissertation (MSc (Plant Physiology))--University of Pretoria, 2005.
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University of Pretoria
2013
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| _version_ | 1867613592525733888 |
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| access_status_str | Open Access |
| author2 | Meyer, J.J.M. (Jacobus Johannes Marion) |
| author_browse | Meyer, J.J.M. (Jacobus Johannes Marion) |
| author_facet | Meyer, J.J.M. (Jacobus Johannes Marion) |
| collection | Thesis |
| dc_rights_str_mv | © 2004 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MSc (Plant Physiology))--University of Pretoria, 2005. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/24614 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:38:35.948Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/24614 Characterisation, synthesis and antimycobacterial activity of naphthoquinones isolated from Euclea natalensis Meyer, J.J.M. (Jacobus Johannes Marion) upetd@up.ac.za Van der Kooy, Frank Euclea natalensis research Naphthoquinone Materia medica vegetable Tuberculosis research Applied ethnobotany south africa UCTD Dissertation (MSc (Plant Physiology))--University of Pretoria, 2005. TB is still one of the world's biggest killers. Immunosuppresion induced by AIDS caused a rise in the incidence of TB during the past decade. The search for new drugs to effectively treat TB remains one of the big challenges facing the scientific community. Drugs from plants have been used for centuries to treat various human diseases with varying degrees of success. South Africa with its big resource of plants and ethnobotanical knowledge is an ideal place to screen for anti- TB compounds. The Zulu tribe of South Africa used the root bark of Euclea nata/ensis A.DC. to treat TB related symptoms. Naphthoquinones isolated from E. nata/ensis proved to have good activity against TB. Nine compounds were isolated from the chloroform extract of E. nata/ensis root material. Three of these compounds were newly isolated from this species (mamegakinone, neodiospyrin and 5-hydroxy-4-methoxy-2-napthaldehyde). The structures of the isolated compounds were confirmed using NMR methods and where possible the HPLC and TLC results were compared to authentic standards. Most of the compounds were tested for anti- TB activity with only mamegakinone, lupeol and betulin not showing any activity (5-hydroxy-4-methoxy-2-napthaldehyde still needs to be tested). The activity of the naphthoquinones, especially 7-methyljuglone, diospyrin, isodiospyrin and neodiospyrin, show promise that these compounds could develop into an affordable medicine to treat TB. The activity of the crude extract against the resistant DP48 110 1 TB strain showed that there are probably unknown active compounds remaining in the extract. The most active compound, 7 -methyljuglone, was synthesised and an improved synthetic pathway was developed. The synthesis of naphthoquinones remains important in order to produce the compounds on a larger scale. This will make further studies into the mode of action, biosynthesis, bioactivity etc. of these compounds possible. Attempts were made to synthesise diospyrin with 7 -methyljuglone as the starting material. These experiments failed up to now. By altering the reaction parameters such as pH and temperature it should be possible to synthesise diospyrin in future attempts. Neodiospyrin were synthesised from reduced 7 -methyljuglone. This synthesis will yield information on the naphthoquinone chemistry and on how to synthesise diospyrin and isodiospyrin. The enzymatic synthesis of naphthoquinones was also investigated with the use of a cell-free extract. These experiments indicated that it might be possible to enzymatically synthesise diospyrin and the other dimers. Plant Science unrestricted 2013-09-06T18:03:56Z 2005-05-20 2013-09-06T18:03:56Z 2004-02-12 2005-05-20 2005-05-13 Dissertation Van der Kooy, F 2004, Characterisation, synthesis and antimycobacterial activity of naphthoquinones isolated from Euclea natalensis, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/24614 > H1217/ag http://hdl.handle.net/2263/24614 http://upetd.up.ac.za/thesis/available/etd-05132005-141255/ © 2004 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | Euclea natalensis research Naphthoquinone Materia medica vegetable Tuberculosis research Applied ethnobotany south africa UCTD Characterisation, synthesis and antimycobacterial activity of naphthoquinones isolated from Euclea natalensis |
| title | Characterisation, synthesis and antimycobacterial activity of naphthoquinones isolated from Euclea natalensis |
| title_full | Characterisation, synthesis and antimycobacterial activity of naphthoquinones isolated from Euclea natalensis |
| title_fullStr | Characterisation, synthesis and antimycobacterial activity of naphthoquinones isolated from Euclea natalensis |
| title_full_unstemmed | Characterisation, synthesis and antimycobacterial activity of naphthoquinones isolated from Euclea natalensis |
| title_short | Characterisation, synthesis and antimycobacterial activity of naphthoquinones isolated from Euclea natalensis |
| title_sort | characterisation synthesis and antimycobacterial activity of naphthoquinones isolated from euclea natalensis |
| topic | Euclea natalensis research Naphthoquinone Materia medica vegetable Tuberculosis research Applied ethnobotany south africa UCTD |
| url | http://hdl.handle.net/2263/24614 http://upetd.up.ac.za/thesis/available/etd-05132005-141255/ |