Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Antiplasmodial- and chloroquine resistance reversal properties of a new diterpene from Croton steenkampianus
Thesis (DPhil)--University of Pretoria, 2008.
Saved in:
| Other Authors: | |
|---|---|
| Format: | Thesis |
| Published: |
University of Pretoria
2013
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613614044610560 |
|---|---|
| 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 | Thesis (DPhil)--University of Pretoria, 2008. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/27220 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:38:56.612Z |
| 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:2263/27220 Antiplasmodial- and chloroquine resistance reversal properties of a new diterpene from Croton steenkampianus Meyer, J.J.M. (Jacobus Johannes Marion) Louw, Abraham Izak upetd@up.ac.za Prozesky, Erwin Antoni Drugs Malaria Vaccine Parasitic disease UCTD Thesis (DPhil)--University of Pretoria, 2008. Malaria remains the most serious and deadly parasitic disease, affecting millions of people mostly in the poorest countries in the world. With no vaccine likely in the foreseeable future, drugs remain the best means of controlling the disease. Plants have provided most of the antimalarial drugs so far and it is likely that more antimalarial drugs will be discovered in this way. A previous study on South African plants yielded very good results on the extract level. In this study Croton steenkampianus leaf extract was selected for isolation of active principles. Bio-guided fractionation of the extract was done on silica column chromatography and Sephadex column chromatography. Five compounds, two favonoids, a triterpene and two new diterpenes, with a novel skeleton were isolated. Compounds were identified with NMR, MS and X-ray crystallography. Antiplasmodial activity of the compounds varied from moderate to excellent, with crotrene A having excellent activity. Further studies on the antimalarial potential of this compound are planned. Cytotoxicity of compounds and extract were determined against human lymphocytes. Results obtained had an ID50 between >16,61 µg/ml. The therapeutic indexes were between 2.75 and 55.18, showing poor to moderate selectivity towards Plasmodium. Crotrene A had the best therapeutic index and more detailed studies on its cytotoxicity are necessary. Resistance to antimalarial drugs is a major problem in effective treatment of the disease. One way of overcoming this problem is combination drugs working synergistically. Chloroquine the most affordable antimalarial drug was combined with the isolated compounds. Two compounds showed synergistic activity with crotrene A having excellent activity, completely reversing chloroquine resistance. This combination of drugs showed no synergistic cytotoxic effects and its potential as a drug will be further investigated. The mode of action of antimalarial drugs can provide useful information about the long term potential and the likelihood of resistance development. Crotrene A was subjected to a basic test to determine a possible mode of action. Results showed a marked effect in the early phase of development (rings). The results suggest a very potent mode of action able to reduce the amount of parasites quickly and this holds promise for further development of this compound. Plant Science unrestricted 2013-09-07T10:57:53Z 2008-08-15 2013-09-07T10:57:53Z 2005-04-20 2008-08-15 2008-08-13 Thesis Prozesky EA, 2004, Antiplasmodial- and chloroquine resistance reversal properties of a new diterpene from Croton steenkampianus, DPhil thesis, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/27220 > H1092/th http://hdl.handle.net/2263/27220 http://upetd.up.ac.za/thesis/available/etd-08132008-090945/ © 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 | Drugs Malaria Vaccine Parasitic disease UCTD Antiplasmodial- and chloroquine resistance reversal properties of a new diterpene from Croton steenkampianus |
| title | Antiplasmodial- and chloroquine resistance reversal properties of a new diterpene from Croton steenkampianus |
| title_full | Antiplasmodial- and chloroquine resistance reversal properties of a new diterpene from Croton steenkampianus |
| title_fullStr | Antiplasmodial- and chloroquine resistance reversal properties of a new diterpene from Croton steenkampianus |
| title_full_unstemmed | Antiplasmodial- and chloroquine resistance reversal properties of a new diterpene from Croton steenkampianus |
| title_short | Antiplasmodial- and chloroquine resistance reversal properties of a new diterpene from Croton steenkampianus |
| title_sort | antiplasmodial and chloroquine resistance reversal properties of a new diterpene from croton steenkampianus |
| topic | Drugs Malaria Vaccine Parasitic disease UCTD |
| url | http://hdl.handle.net/2263/27220 http://upetd.up.ac.za/thesis/available/etd-08132008-090945/ |