Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Structure elucidation of antiplasmodial sesquiterpene lactones from Vernonia staehelinoides and Oncosiphon piluliferum
Dissertation (MSc (Chemistry))--University of Pretoria, 2007.
Saved in:
| Other Authors: | |
|---|---|
| Format: | Thesis |
| Published: |
University of Pretoria
2013
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613531786969088 |
|---|---|
| access_status_str | Open Access |
| author2 | Vleggaar, Robert |
| author_browse | Vleggaar, Robert |
| author_facet | Vleggaar, Robert |
| collection | Thesis |
| dc_rights_str_mv | © 2006, 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 (Chemistry))--University of Pretoria, 2007. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/23974 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:37:38.105Z |
| 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:2263/23974 Structure elucidation of antiplasmodial sesquiterpene lactones from Vernonia staehelinoides and Oncosiphon piluliferum Vleggaar, Robert ppillay@csir.co.za Pillay, Pamisha Medicinal plants Materia medica Sesquiterpene lactones Vegetable Malaria treatment UCTD Dissertation (MSc (Chemistry))--University of Pretoria, 2007. Malaria continues to be a major cause of mortality and morbidity especially in Sub-Saharan Africa. The emergence and spread of drug resistant parasites has highlighted the need for new chemically diverse, effective drugs. Historically, one of the major sources of antimalarial agents and novel template compounds has been higher order plants. The widespread use of medicinal plants for the treatment of malaria in South Africa represents a diverse resource of potential antimalarial drugs. Two South African plants, Vernonia staehelinoides and Oncosiphon piluliferum, were identified as potential sources of new antimalarial drugs through a national multidisciplinary-consortium project aimed at scientifically validating South African medicinal plants for the treatment of malaria. The in vitro antiplasmodial activity of extracts of these plants warranted further investigation to identify the biologically active components. Bio-assay guided fractionation based on in vitro antiplasmodial activity against the D10 P. falciparum strain was used to identify the compounds responsible for the observed activity. Compounds were purified using silica gel column chromatography. The structures of the isolated compounds were elucidated using spectroscopic techniques. Bioassay-guided fractionation of the organic extracts of V. staehelinoides leaves identified a pair of structurally-related hirsutinolides with significant in vitro antiplasmodial activity. The compounds were found to be cytotoxic at similar concentrations but proved to be interesting scaffolds for potential structure-activity relationship studies. Three germacranolides and two eudesmanolides were identified through bioassay-guided fractionation of the organic O. piluliferum extract. Selected derivatizations were conducted in order to fully characterize the compounds. The absolute configuration of the major active germacranolide was determined using Mosher's method. The effect of the reduction of the <font face="symbol"> a</font>-methylene group of the major active germacranolide on antiplasmodial activity and cytotoxicity was also investigated. The 5 compounds and the reduction product were found to possess varying degrees of in vitro antiplasmodial activity and cytotoxicity. None was sufficiently active or selective to be a viable drug candidate but the potential for further structure-activity relationship studies exists. Chemistry unrestricted 2013-09-06T16:18:26Z 2007-04-16 2013-09-06T16:18:26Z 2006-09-07 2007-04-16 2007-04-16 Dissertation Pillay, P 2006, Structure elucidation of antiplasmodial sesquiterpene lactones from Vernonia staehelinoides and Oncosiphon piluliferum, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/23974 > http://hdl.handle.net/2263/23974 http://upetd.up.ac.za/thesis/available/etd-04162007-102438/ © 2006, 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 application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf University of Pretoria |
| spellingShingle | Medicinal plants Materia medica Sesquiterpene lactones Vegetable Malaria treatment UCTD Structure elucidation of antiplasmodial sesquiterpene lactones from Vernonia staehelinoides and Oncosiphon piluliferum |
| title | Structure elucidation of antiplasmodial sesquiterpene lactones from Vernonia staehelinoides and Oncosiphon piluliferum |
| title_full | Structure elucidation of antiplasmodial sesquiterpene lactones from Vernonia staehelinoides and Oncosiphon piluliferum |
| title_fullStr | Structure elucidation of antiplasmodial sesquiterpene lactones from Vernonia staehelinoides and Oncosiphon piluliferum |
| title_full_unstemmed | Structure elucidation of antiplasmodial sesquiterpene lactones from Vernonia staehelinoides and Oncosiphon piluliferum |
| title_short | Structure elucidation of antiplasmodial sesquiterpene lactones from Vernonia staehelinoides and Oncosiphon piluliferum |
| title_sort | structure elucidation of antiplasmodial sesquiterpene lactones from vernonia staehelinoides and oncosiphon piluliferum |
| topic | Medicinal plants Materia medica Sesquiterpene lactones Vegetable Malaria treatment UCTD |
| url | http://hdl.handle.net/2263/23974 http://upetd.up.ac.za/thesis/available/etd-04162007-102438/ |